The award banquet Fletch interrupts is in honor of Fred Dorfman. Fred Dorfman the name of Kent "Flounder" Dorfman's brother in Animal House (1978), which was originally going to feature Chevy Chase as Eric "Otter" Stratton. Otter was eventually played by Tim Matheson, who also appears in this movie as Alan Stanwyk.

When Mr. Underhill comes to collect the money for his lunch bill, Fletch searches for the time on his non watch-wearing wrist. This is a trademark of Chevy Chase.

Harold Faltermeyer replaced Tom Scott as the film's composer. However, Scott's name is visible on the early poster releases for the movie as well as the trailer included on the DVD.

Fletch tells beach drifter in one scene that he "feels like a hundred dollars". This line is also said by Ty Webb in Caddyshack (1980), a role also played by Chevy Chase.

Gregory McDonald, the author of the Fletch novels, had casting approval over the film. He rejected both Mick Jagger and Burt Reynolds before he decided on Chevy Chase for the lead.

Continuity

When Fletch confirms his flight at the airline counter, he is told he is confirmed on Flight 441. Later, when he is reading his letter outlining Mr. Stanwyk's plan, he says "Mr. Stanwyk boarded Pan Am flight 306."

A picture jumps back on the wall after being knocked off when Fletch is thrown against the wall.

After Fletch breaks into the real-estate office and is subsequently chased by the Doberman, he hurries to his car. The glare indicates that the driver's-side window is up, but when the dog jumps on the hood, the window is down and Fletch rolls it up.

When Fletch and Alan arrive at Alan's house to discuss their potential 'business' arrangement, the driveway is wet as the car parks. As they both exit the car, the driveway pavement is suddenly dry.

During Fletch's car chase with the police, the motorcycle cop is flipped when Fletch jumps an embankment. When we see the cop flipped, his unstrapped helmet is falling away from his head, but when he hits the grass, his helmet is firmly secured on his head. This whole scene has apparently been fixed/re-edited in the 'Jane Doe Edition' of the movie as now the helmet stays on the cop's head securely during the whole scene.



Factual errors

When Fletch is getting a physical, a chest X-ray in the background is hung up backwards--unless of course, that particular patient had a rare congenital disease. "Please don't submit "mistakes" that were clearly intended by the filmmakers, for humorous purposes."

Fletch flies into and out of Provo Airport. In 1985, Provo Airport had neither a tower nor commercial traffic. The closest airport would have been Salt Lake International Airport.

When Fletch lies in bed to watch TV, he turns it on with a remote control. The TV has a dial to change the channel and a push-button on/off volume switch.



Incorrectly regarded as goofs

The ticket agent informs Fletch, who she thinks is Mr. Stanwyk, the seat beside his on the next-day flight to Rio is occupied by Sally Ann Cavanaugh, who is connecting from Provo. Later, when Fletch calls his newspaper office, he asks Larry to check LA hotels for Sally Ann Cavanaugh. Why would she need a hotel if she is on a connecting flight? Because she has a very long connection, about 30 hours, so she must spend the night in LA. Fletch knows this because the guy with the shotgun told him she moved out in the morning a day before the evening flight to Rio.

Alan Stanwyk's jet, which he uses to run drugs from South America, is a Cessna Citation II, which has a maximum range of 2300 miles. The closest point of South America is about 3200 miles away from LA, but all he needs to do is stop midway, like in Mexico City, to refuel. Then he could easily reach Colombia, Venezuela, Equador, or Peru. Of course, he can stop for refueling more than once too. It's never definitively established that Alan actually flew to South America, this claim is based only on a humorous estimate from a couple of dim-witted mechanics and vague hearsay from Gummy. It could well be somewhere much closer, like Mexico.

Fletch looks at a picture of Sally Ann Cavanaugh as the mother turns the pages in the photo album. We see Fletch holding the picture and the album's pages aren't being flipped. She was trying to turn pages but Fletch kept stopping her. Only one page actually did get turned and it had the same photo as the previous page.

When Fletch is called in to assist during the postmortem scene, the doctor comments on the size of the dead patient's spleen during its removal. The doctor is working on the dead patient's right side, but the human spleen is on the left side (unless the dead patient has a very rare congenital condition). Chevy Chase and M. Emmet Walsh are both comedic actors. "Please don't submit "mistakes" that were clearly intended by the filmmakers, for humorous purposes."

Chevy Chase is 6'4". Tim Matheson is 6'2". Even with the same waist size, Stanwyk's pants should be way too short for Fletch. The height difference only applies to actors, while their characters, according to the plot, have the same height and build. If actors can play characters of age, race or even gender different from their own, they can certainly play characters of a slightly different height.



Revealing mistakes

When Fletch takes a picture of the phony deed, there is no flash from his camera, yet the picture he shows Mrs. Stanwyk has a flash visible in it.



Audio/visual unsynchronized

When the motorcycle cop yells for Fletch to "Pull over," his mouth does not match the words.

When Fletch is "quitting", his boss moves his mouth twice on the same piece of dialog between cuts.



Crew or equipment visible

As Fletch starts upstairs in the Cavanaugh house, a crew member is visible in the doorway to the right of the stairway.

A crewmember's hand is visible at the right side of the screen next to Alan Stanwyk's body after he is shot.



Errors in geography

When Fletch is escaping from the shotgun-wielding hillbilly in what is supposed to be Provo, Utah, which has no palm trees, right after his rear window is shot out, palm trees are obvious in the background, indicating that the scene was shot elsewhere, most likely southern California.



Character error

When the Underhills are first seen, Mrs. Underhill calls her husband Tom. Later, he introduces himself as Ted at Mrs. Stanwyk's cabana.

When Alan Stanwyck holds the "Jane Doe" letter near the end of the film, it states that he was married four years ago, but it had been established that it was eight years prior, and when they read the letter they say eight.

Mr. Underhill complains about lunch being $400, but that total is much too low: Fletch ordered 2 bottle of Dom Perignon at $100 a bottle, 2 portions of caviar at $80 each. He gives the waiter $30 and tells the servers to give each other $20. That already comes to $430. The total does not even include the two orders of Lobster Thermidor or whatever the Underhills themselves had.

When Fletch discovers Alan Stanwyk's plan to kill him by burning him up inside Alan's car to make people think it was a car wreck, he replies that everyone will think Stanwyk died in the car wreck "because of the same bone structure". Even in 1985, before DNA became an established forensic tool, dental records would have been used. It is very possible that Stanwyk thought of that and had a plan to ensure there would be no teeth for dental-records checks.

Every time the name "Stanwyk" is spelled in the first part of the film, it is spelled "Stanwyk". Fletch spells the name for his research assistant (Geena Davis) "Stanwyck"--no "C." The film credits spell it "Stanwyk," but the ticket-counter computer screen says "Stanwyck."