The role of Louis Tully was originally written for John Candy.

The role of Peter Venkman was originally written for John Belushi.

According to Ivan Reitman and Harold Ramis in the DVD Commentary, in Dan Aykroyd's original rough draft of the movie, the story was going to take place in the future and that there would be teams of Ghostbusters like there are paramedics and firefighters (thus explaining basing the Ghostbusters HQ in a firehouse). According to Reitman, such a film would cost "at least $300 million in 1984 dollars". So Harold Ramis was brought in to rewrite the script and bring it into modern times.

The role of Winston was originally written for Eddie Murphy.

Gozer was originally going to be played by Paul Reubens, who turned down the role. In the original script, Gozer appeared as a normal man in a business suit.

Punk rocker Anne Carlisle was originally offered the role of Zuul, but turned it down.

Sandra Bernhard was originally offered the role of Janine.

Dan Aykroyd's original version of the script began with the Ecto-mobile flying out of Ghostbusters HQ, but director Ivan Reitman suggested that it would be better to show how the team got started.

Dana's apartment building actually exists at 55 Central Park West in New York City. The building is actually only 20 stories high. For the film, matte paintings and models were used to make the building look bigger and with more floors.

The Stay-Puft marshmallow man was originally supposed to come up out of the water right next to The Statue of Liberty, to get a contrast of size, but the scene was too hard to shoot.

On the set, Dan Aykroyd referred to the "Slimer" ghost as the ghost of John Belushi.

Though never referred to in the script, the green ghost the guys bust in the hotel was dubbed "Onionhead" by the crew, because of its horrid smell. A scene where the ghost haunts two newlyweds showed this characteristic, but it was cut. Since it was never referred to in the movie, the writers of the animated show came up for a different name for the green ghost: Slimer.

The eggs which fry themselves are sitting next to a package of "Sta-Puft" marshmallows. There is also a large advertisement for "Sta-Puft" marshmallows (complete with the marshmallow man) visible on the side of a building.

Many sequences were shot but removed from the film (a couple of the following were added as extras to the Criterion Collection CAV laserdisc release) : - Several shots in the sequence where Venkman, Stantz, and Spengler are thrown off campus were cut. - Several scenes throughout the film with Janine and Egon were cut. - The first time Venkman leaves Dana's apartment, he says to Louis "What a woman." - The "green slimer" ghost is discovered by two newlyweds at the Hotel Sedgewick. Also cut was a Ghostbuster inspection of the room. - A policeman tries to ticket the Ectomobile, but the car won't let him. - Bill Murray and Dan Aykroyd play two bums that witness Louis being chased by the terror dog. - Ray and Winston inspect Fort Detmerring, where Ray dresses in an old General's coat and falls asleep. When he awakes, he sees a female ghost above his bed. This part of the sequence was kept and used in the montage in the middle of the film. - Louis encounters two muggers in Central Park during the ghost montage. - Venkman and Stantz discuss matters with the mayor outside City Hall. - The Stay-Puft Marshmallow Man sequence ends with his large hat falling to the ground. Some deleted shots appear in the film's trailers.

In the middle of the film's initial release, to keep interest going, Ivan Reitman had a trailer run, which was basically the commercial the Ghostbusters' use in the movie, but with the 555 number replaced with a 1-800 number, allowing people to call. They got a recorded message of Bill Murray and Dan Aykroyd saying something to the effect of "Hi. We're out catching ghosts right now." They got 1,000 calls per hour, 24 hours a day, for six weeks.

When Alice the librarian is queried as to whether anyone in her family had ever had any history of mental illness, she replies she had an uncle who thought he was St. Jerome. Jerome is the patron saint of librarians.

The demonic voice of Dana/Zuul was performed by director Ivan Reitman. The voice of Gozer was provided by Paddi Edwards.

In rehearsal, Bill Murray (Venkman) teased Czech model Slavitza Jovan (Gozer) about her pronunciation of the line "Choose and Perish", which sounded to him like "Jews and Berries"(!) and he'd say "There are no Jews and Berries here!"

Most of the deleted scenes are "restored" in the novelized adaptation of "Ghostbusters".

The original script had a budding romance between the cynical receptionist Janine and the blissfully out of it Egon, but most of it was edited out of the film. The special edition DVD features a deleted scene of Janine giving Egon a coin for luck before he goes off with the other Ghostbusters to fight Gozer; they are interrupted by Venkman. The relationship between Janine and Egon was explored more in the animated series that followed.

The interiors for the hotel scene were filmed (mostly) at the famous Biltmore Hotel in Los Angeles, on the corner of 5th and Grand. This famous location has been used for hundreds of films, TV shows, commercials and even a few music videos. The three doors that the Ghostbusters walk through in the movie are actually located on the entrance on 5th St. The Grand Avenue entrance leads you to the main lobby, which used to be the hotel ballroom, as seen in the film. (The ceiling is a dead give away.) The room's formerly solid walls have been replaced by glass doors (at the entrance) and archways. The reception desk is where the long banquet table was located in the film. To the right of that would have been the bar that Egon blasts. If you go into the bar to the right of the main lobby, there is a picture of the old ballroom on one of the walls, giving you a better perspective of what the room looked like in the early '80s.

Flashbulbs were used on the business end of the proton pack weapons so that the special effects creators could properly synch up the effects with the action (most visible in the dining room scene, frame by frame, when capturing Slimer).

All the college scenes were filmed at Columbia University in New York, including the fictional Weaver Hall office/lab interiors. Director Ivan Reitman decided to use an actual on-campus office instead of a soundstage so the film crew could film indoors if the weather turned bad, rather than lose a day's filming. Columbia University agreed to all this, on the condition the school not be mentioned by name on-camera.

The firehouse set the Ghostbusters use as HQ was remodeled and used once again as the mechanic shop in The Mask (1994).

The original premise of "Ghostbusters" had three main characters: John Belushi, Dan Aykroyd and Eddie Murphy. They fought ghosts in S.W.A.T. like suits using wands instead of guns. The ghost named Slimer was known as 'Onionhead', and at the end of the movie the Ghostbusters franchise was all over the United States. John Candy also was slated to play Louis. However, with Belushi's death and characters backing out, the script was rewritten and new actors cast.

Storyboarded but never shot included: - A scene with Egon testing the proton pack, which is charged by being plugged in. The pack melts the plug. - A model's mink coat comes to life on a runaway. Note that this scene does happen in Ghostbusters II (1989) to a woman on the street.

Early publicity for the film was a teaser campaign featuring just the "no ghosts" logo. As the campaign built, the Ectomobile was also driven around the streets of Manhattan.

Exterior scenes of the Ghostbusters headquarters were filmed at the Hook and Ladder #8 Firehouse in the Tribeca section of New York City. Inside the firehouse are a Ghostbusters sign and photos taken with the cast and crew.

After the Stay-Puft Marshmallow Man is destroyed there is a shot of a man down on the street being deluged by a huge amount of marshmallow goo. Due to the extreme angle of the shot most viewers don't realize that this is Walter Peck, until he screams, "I HATE you, Venkman!". A cut scene (included on the DVD) took place a few moments before, at the same angle, where Peck tells the police to go up to the roof and arrest the Ghostbusters.

The "marshmallow" goo was actually shaving cream. More than fifty gallons was dumped on Walter Peck almost knocking him to the ground.

The schedule for getting the movie into theatres for its scheduled release date in summer 1984 was so tight, director Ivan Reitman said that the final print included incomplete special effects shots and errors like "wires showing" but, "remarkably, people didn't care".

One scene shot for the film but later deleted shows Ray and Winston on a call and Ray ends up in Canadian Mounties outfit. Production stills from this scene appear in the published version of the film script.

Initally, Ray Parker Jr. was having trouble writing the theme song to the film. The problem was solved when he saw the TV commercial for the Ghostbusters business in the film which inspired him to write the song like a advertising jingle for the business. The song was a #1 hit for three weeks.

When Venkman mentions the time Spengler tried to drill a hole in his head, Spengler's response ("That would have worked if you hadn't stopped me") was actually ad-libbed by Harold Ramis.

The Stay-Puft Marshmallow Man suits cost Approximately $20,000 apiece. Three were made and all were destroyed during filming.

The Ectomobile was originally painted black until it was pointed out that most driving would be at night and the car would be difficult to see. It was then repainted white.

The firehouse used is actually two different firehouses that are in two different cities. The exterior is in NY, while the interior is in downtown Los Angeles. The LA firehouse is very popular with filmmakers and has been used in many movies.

Bill Murray agreed to do this movie only on the condition that Columbia finance a remake of The Razor's Edge (1946) with him as the star. The remake was made (The Razor's Edge (1984)).

The bum that Bill Murray played in a deleted scene looks and acts just like his character on Caddyshack (1980) (and also sports a golfing cap).

The party scene where Louis Tully (Rick Moranis) mingles with his party guests (commenting on the price of the salmon, and so on) is not only taken in one continuous shot, but is almost entirely improvised.

Huey Lewis and the News turned down an offer to write and record a theme song for Ghostbusters. They later sued Ray Parker Jr. for plagiarism, citing the similarities between his theme song and their earlier hit "I Want a New Drug."

Lindsey Buckingham was approached to write the theme song to after the successful collaboration for Vacation (1983) ("Holiday Road"). He declined.

There was a even more ferocious version of the Librarian Puppet that was going to be used, but it was rejected. However, it was recycled and used in another successful Columbia Pictures film released one year after this one, Fright Night (1985).

Before the release of Home Alone (1990), this was the highest-grossing comedy of all time.

In the original draft for Bill Murray's character, sexual obscenities were written on Peter Venkman's door; but Ivan Reitman wanted to make his film a target audience for families so the phrase "Venkman Burn in Hell" was added. In fact, this is a nod to the final scene in Stephen King's Carrie (1976) - where there is a for-sale sign on the vacant lot where Carrie's house once stood, and someone has graffitied it with "Carrie Burn in Hell".

Voted number 28 in channel 4's (UK) "Greatest Family Films".

Scenes in the montage sequence of the Ghostbusters running around New York (and also driving in the Ecto-mobile) were done on the first day, largely without film permits. In one scene, someone who looks like they might be a security guard begins chasing after them, and Dan Aykroyd can be seen actually driving the Ecto-mobile.

In the scene when the terror dogs (Zuul and Vince Clorthow) come to life, were actual statue designs on an old church in Philadelphia.

As revealed in an interview with Mix Magazine Online the hit song 'Ghostbusters' was created 4:30 in the morning when after almost 2 long days of trying to create a song Ray Parker Jr. saw a commercial for a drain company that reminded him of a scene from the film. That commercial helped him coin the popular line "Who you gonna call?"

The character of Winston was initially written to be a guard at the Ghostbusters firehouse. Also, in earlier drafts of the script, Winston was the one who conjured up the Stay-Puft Marshmallow Man.

The phone number for the Ghostbusters as it appears on the television ad that Dana sees in her apartment is 555-2368.

When the Stay-Puft Marshmallow Man arrives, Ray says that he remembered the Stay-Puft marshmallows from when he use to go camping at Camp Wauconda. Camp Wauconda is an actual boy scout camp outside of Peoria, IL.

The electric shock experiments that Venkman conducts on the college students parodied the real life Milgram Experiments, which related to obedience. In the early 1960s, Yale psychologist Stanley Milgram wanted to see if test subjects would administer electric shocks of increasing voltage to fellow test subjects (actually actors pretending to be shocked) based on the commands of an authority figure. Most of them did.

Michael Keaton turned down both the roles of Dr. Peter Venkman and Dr. Egon Spengler.

Chevy Chase turned down the role of Dr. Peter Venkman, he claimed that the script used in the movie wasn't the original script and in the original script was very dark and even more scarier.

The movie's line "Dogs and cats living together! Mass hysteria!" was voted as the #68 of "The 100 Greatest Movie Lines" by Premiere in 2007.

The movie's line "Well, there's something you don't see every day." was voted as the #19 of "The 100 Greatest Movie Lines" by Premiere in 2007.

The music video for the song "Ghostbusters" by Ray Parker Jr., directed by Ivan Reitman, featured a number of celebrities who did not appear in the film. This included Chevy Chase, John Candy, Danny DeVito, Peter Falk, 'Melissa Gilbert', Carly Simon, Teri Garr, Irene Caraand George Wendt. In addition, the Ghostbusters themselves danced down Times Square right behind 'Ray Parker Jr'.

The lively chorus shouting the words "Ghostbusters" through the song were made up of the only people Ray Parker Jr. could find quickly enough to help him meet his deadline: his young girlfriend and her friends.

The floating Sigourney Weaver special effect is an actual physical effect, not an optical effect. The actress was put in a full body cast and attached to a post that was hidden in the curtains. According to the commentary, this effect came from director Ivan Reitman's Broadway experience.

Harold Ramis says that his character's name was built from two parts. The first name (Egon) was taken from a Hungarian refugee he went to grammar school with, and Spengler was from historian Oswald Spengler.

Christopher Walken, John Lithgow, Christopher Lloyd and Jeff Goldblum were all considered for the role of Dr. Egon Spengler.

Harold Ramis really had no intention of starring in the film, only writing it. But he decided to star in this film as Dr. Egon Spengler after he felt he was the best person suited for the role.

The probe Venkman uses in Dana's apartment is actually a United Technologies/Bacharach 300 Series "Sniffer", normally used to locate utility gas leaks or low-oxygen hazards. The squeeze-bulb is standard. It is conceivable such a detector could be modified to find other gases-perhaps even paranormal ones.

Jean Kasem's feature film debut.

Continuity

In the overhead shot when the Marshmallow Man is first hit with proton beams, he's not wearing his red tie. Billy Bryan, who was wearing the suit, recounts that when he was about to attach the tie, effects artist Joe Viskocil was busy adding flash bulbs and spark generators to the Mr. Stay Puft's bib. Bryan didn't want to mess it up, and forgot to attach the tie.

Winston's name tags say "Zeddemore." The credits spell his name as "Winston Zeddmore."

When Dana gets out of the cab, her groceries include a green leafy vegetable with a large white stem. When she gets to the hall, it has become completely green lettuce. It changes to celery while she is talking to Louis. When she sets it on the counter it is still celery, In the next shot the item on the counter is lettuce. After the eggs start frying on the counter top it changes to lettuce and celery, each pointing in opposite directions. When Venkman is checking out the apartment, they both point the same direction.

When the gang is about to enter Dana's building, a red-haired extra is visible in two different crowds that are supposed to be facing each other.

(at around 24 mins) When Peter goes to Dana's apartment for the first time, the piano cover goes from being closed, to open, to closed, to open again.



Factual errors

Dr. Peter Venkman claims that he has doctorates in psychology and parapsychology. Later, he says that he sedated Dana Barrett/Zuul with Thorazine. Doctors of psychology and parapsychology are not MD's, so they can't prescribe or administer drugs, especially a controlled substance like Thorazine. While someone as immoral as Venkman would, regardless of his credentials, administer such a drug, Venkman had no means by which to get the drug being that he cannot write prescriptions.

The ghost busters would not be authorized to have blue lights in their car . Blue lights on cars in the state of NY are restricted to volunteer fire fighters , and their immediate family members.

When Walter Peck is explaining to the mayor why the EPA was investigating the Ghostbusters, he states that the Ghostbusters were defrauding people by putting on "some laser light show". Fraud would be investigated by the District Attorney's office (or some other law enforcement agency) as opposed to the EPA.

In the opening scene in the library, the librarian passes the card catalog. The cards start flying out. When they float down, it is apparent that they have no print on them and are completely blank.

When the Ghostbusters are climbing the stairs in Dana's building, the staircase is square with a large central opening and ornate railings. And there is an upward looking shot that shows this square stairway continuing up to the top of the building. But when they reach the 22nd floor, the staircase is now a narrow rectangular one with plain iron railings.



Incorrectly regarded as goofs

Ray quotes a Bible verse, which he says is Revelation 7:12. It's actually Revelation 6:12. Ray also forgets some words, while Winston adds extra words. But Ray and Winston were trying to remember the verse (as Ray says he "remembers" the verse) so they may not remember all of it.

When Venkman is explaining that Gozer will take the form of whatever they think of, he uses J. Edgar Hoover as an example. The fact that he used J. Edgar Hoover as an example would mean that he had to think of him, if only for a second. Gozer should've assumed the form of J. Edgar Hoover. However, it is possible that Ray understood what Gozer meant at the same moment Venkman did and that he thought of Mr. Stay-Puft before Venkman thought of J. Edgar Hoover.

Venkman says that Gozer was worshiped by the Hittites, Babylonians, and Sumerians in 6000 BC. The Sumerians first came into history around 4000 BC, the two Babylonian Empires lasted from 1900 to 1600 BC and 626 to 539 BC, and the Hittite empire lasted 1600 to 717 BC. However, 4000 BC is the earliest

known

date regarding the Sumerians, they could have been around much earlier. The other groups existed in the same general region and grew out of earlier cultures, so a set of Gozer cults could have existed in 6000 BC in the cultures that the Hittites and Babylonians came from. (A simpler explanation is that Venkman has no idea of what he's talking about.)

Venkman tells Egon he has Dana "whacked up with 300cc" of Thorazine, a relaxant and anti-psychotic. It's more common to describe dosage by weight, not volume, so he likely meant 300 mg, which as a single dose is exceedingly high even for severely disturbed patients. Given the vague nature of demonic possession, a dose that high could have been necessary.

When Winston and Ray are in the car talking about the Bible verse, Winston is in the driver's seat. When they pull up to the HQ after the explosion, Ray gets out of the driver's seat. They may have stopped and switched seats between the scenes.



Revealing mistakes

A heavy object used to destroy Dana's apartment wall clearly flies as the wall explodes.

When Mr. Stay-Puft walks through Columbus Circle, his body overlaps a street light in the foreground, even though he should be far behind it.

(at around 39 mins) One shot of the Ectomobile during the first montage is flipped; the logo faces the opposite direction.

(at around 52 mins) Dana's chair is dragged into the kitchen. After the door has shut, the track used to drag the chair along is visible on the floor.

When the Ghostbusters are about to enter the building and the ground begins to break apart, the pieces of ground are not all solid. What appears to be a brown sheet billows out as one piece slopes down.



Audio/visual unsynchronized

When Louis runs toward the Tavern on the Green he says, "I'm going to bring this up at the next tenant's meeting. There's not supposed to be any pets in the building," without moving his mouth.

When the Ghostbusters vehicle is pulling out of their HQ to head to their first call, the editors speed up the film to make the car look like it is speeding off. On the street, one block behind, you can see a person walking across the street and he speeds up super-fast as the car appears to speed off.

When Peter and Raymond enter the library, things we hear aren't what they are actually saying by their mouth movement.



Crew or equipment visible

When Dana/Zuul levitates as Venkman is counting to three, part of the device used to lift her up is visible under her middle back area.

When the Ghostbusters are hit by Gozer's finger lightning, the stunt cable used to pull the Ghostbusters through the air visibly moves out of frame in the upper left.

When the Marshmallow Man is walking down the street (seen from the Ghost Busters' perspective, before the tiny hydrant explodes) the cables used to maneuver the character's face are visible by his right foot.

As the camera pans down on the rooftop when the gargoyles come alive, the sound stage floor briefly appears at the bottom left corner [Widescreen version only]

When Venkman vaults over his office partition to meet Dana, a crew member's legs are moving behind the file cabinets to the left.



Errors in geography

The Ectomobile is first seen on Columbus Avenue passing West 89th Street, then moments later in another part of town, then back on Columbus Avenue and turning onto West 88th Street, coming to a stop outside a townhouse which is actually 420 East 78th Street.



Plot holes

After the grid is shut down by Peck, he then has all four of the Ghostbusters arrested. For some reason, Janine is still free as a bird when she herself was there during this incident. On the other hand, Winston and Ray weren't there, yet they were arrested, even though Peck had never met them until that point.

In the elevator scene at the hotel, Venkman says the proton packs are nuclear accelerators. It is never explained where and how they got the material to power the packs, such as plutonium and uranium.

Dana Barrett's musical partner (possible boyfriend) asks her, "who is he (Dr. Venkman)"? By this time, the Ghostbusters had run numerous commercials, been interviewed on television, and shown on countless magazine covers, and he didn't recognize him? Even someone who did not own a television and had never read any magazines would have recognized him.



Character error

Ray declares that the phenomena they are witnessing may be as important as "the Tunguska blast of 1909." It actually occurred on June 30, 1908.

Near the beginning of the film, Venkman conducts an experiment in which he says he is using Negative Reinforcement. Two test subjects guess the symbol on the back of the card. Venkman administers electric shock for wrong answers, and gives praise for correct answers. Psychologically and Scientifically speaking, Negative Reinforcement is the subtraction of a variable in order to reinforce/increase the frequency of a desired behavior. Venkman is actually engaging in Positive Punishment, the addition of a variable or stimulus (electric shock) to decrease the frequency of a behavior (wrong answers). In Behavioral Psychology, Negative and Positive refer to the addition or subtraction of a variable in order to enhance or discourage a given behavior.

In the meeting with the Mayor, Winston tells him he's 'only been working with the company for a couple of weeks'. If fact, thanks to Peter being seen arranging a date with Dana for a few days after Winston's first day, he's actually only been working for them for less than a week at that point.

After the containment unit is shut down, Peck says that the Ghostbusters are 'in criminal violation of the Environmental Protection Act', which does not exist. He could mean the National Environmental Policy Act (NEPA), Clean Water Act (CWA), Clean Air Act (CAA), or one of several other federal environmental policies. Also, it is normal for a state agency representative to deal with any potential violations before requesting assistance from the EPA.

Winston tells the Mayor that he has been with the company for a few weeks. However, he was hired the same day that Venkman met Dana after her rehearsal. He arranged to meet her on Thursday evening, with no indication that it was not the Thursday of that very week. Therefore, Winston could only have been with them for less than a week.