Sylvester Stallone decided that for the shooting of the fight, he and Dolph Lundgren should hit one another for real, so as to increase the intensity of the scene. After doing three takes of Rocky taking shots to ribs, Stallone felt a burning in his chest, but ignored it. Later that night, he had difficulty breathing and was taken to a nearby emergency room. It was discovered that his blood pressure was over 200, and he had to be flown on a low-altitude flight from Vancouver, Canada to St. John's Hospital in Santa Monica, where he remained in intensive care for four days. What had happened was that Lundgren had punched him so hard in the chest, Stallone's heart had slammed up against his breastbone and began to swell, cutting off the blood supply and restricting the oxygen flow throughout the body. . However, when asked about whether or not it really happened while answering a series of fan questions in a 2021 interview with the Guardian, Lundgren claimed to have no recollection of the incident. "I don't know," he said. "[Stallone] keeps talking about it, so maybe he's right. He did go to the hospital, but I don't know whether it was my punches or the fact that he was so overworked as the director, actor and writer. We shot those 15 rounds over two or three weeks, eight or 12 hours a day, so you're throwing thousands of punches. If you don't connect, it looks a bit fake, but it doesn't mean you want to hurt the other guy. But there were no hard feelings." He went on to explain that stand-ins and stunt doubles were rarely used, and that he has performed the majority of his own stunts and fight scenes--but that this has changed in more recent years. "Back in the day, you had to do it all yourself: Rocky IV, The Punisher, Masters of the Universe, all the Expendables," he said. "I've jumped from a motorcycle to a truck; dangerous things I would never do now. Staying physically fit over the years has been nice. There aren't many actors who can stay physically fit for a long time. Part of the game is trying to look fit, at least."

"Rocky IV" became the highest-grossing film in the "Rocky" series to date, taking in just over 300 million dollars worldwide.

During filming, Dolph Lundgren and Carl Weathers really did not get along and got into an altercation. Lundgren threw Weathers into a corner of the boxing ring. After that, Weathers shouted profanities at Lundgren while leaving the ring and announced that he was calling his agent and quitting the movie. Only after Sylvester Stallone forced the two actors to reconcile did the movie continue. This event caused a four-day work stoppage while Weathers was talked back into the part and Lundgren agreed to tone down his aggressiveness.

James Brown is seen performing the song "Living In America" prior to the Creed vs. Drago match. The song was released as a single from the movie's soundtrack and became Brown's first Top 40 single in eleven years, and the last of his career.

Over 8,000 people auditioned for the part of Ivan Drago. Dolph Lundgren was first turned down by the casting directors for being too tall but later on, he got the chance to send photos and meet Sylvester Stallone who told him he had a good chance to get the part, but advised him to gain twenty pounds of muscle. In total, it took Lundgren several months to win the part.

Continuity

During the first round of Rocky's fight with Drago, there are several shots of Paulie and Duke with blood on their shirts, when Rocky has neither been back to his corner, nor is he yet bleeding.

When Rocky is driving and thinking about Drago, there is a flashback to the Drago/Apollo fight, but one of the shots of Drago is actually taken from the upcoming Rocky/Drago fight, because the trunks are the wrong color and Drago is bleeding

Before the fight with Creed and Drago, just after the James Brown dance sequence, Creed points at Drago without gloves on, telling him he is going down. Then in the next shot, Creed has his boxing gloves on.

When Apollo is in his pool throwing balls to the dogs, he throws all the balls in his hand, then when it cuts to a different angle, all the balls are back in his hand.

Rocky has a third private fight with Apollo at the end of Rocky III (1982). Rocky's son was about 3-4 years old in that movie. This movie starts with Rocky arriving home immediately after that fight with Apollo, but now his son is 8-9 years old.



Factual errors

Ivan Drago should have immediately been disqualified when he viciously grabbed Rocky by the throat and punched him after the bell sounded ending the second round of their match.

When Dragos' Manager is yelling in Russian at Dragos' corner man, the caption reads " You trained this fool, he's a disgrace." If you listen carefully he is actually speaking english, and he says " This stupid jerk is unbelievable, he is nuts."

Even if Drago won the fight against Rocky he wouldn't have been seen as a hero, he would've been prosecuted for insulting the Russian Prime Minister and other members of the Politburo.

The movie closes with Rocky saying the following to his son, who's watching the live broadcast of the Rocky-Drago fight on TV. "I just want to say one thing to my kid who should be home sleeping. Merry Christmas, kid! I love you!" But the fight is in Moscow, and Rocky Jr. is watching the fight from the Balboa home in Pennsylvania, which is eight hours behind. In the probable event that the fight aired in prime time in Moscow, it was early afternoon in Pennsylvania; not a time when a child would normally be sleeping.

In the intro with the stylized American and Soviet boxing gloves, the sickle and hammer symbol is topped with a gold star. It should be red (gold border on red background.)



Incorrectly regarded as goofs

During the Creed/Drago fight, the referee tries to stop the fight and then gets shoved back by Drago. Even though, that would have automatically stopped the fight and Drago would've been disqualified, as fighters are not permitted to assault the referee, the filmmakers didn't address this fact because there wouldn't have been a way for the story to move forward, which was for Rocky to avenge his friend.

Drago is seen practicing and registering punches over 2,150 pounds per square inch, which is impossible. Most boxing punches that have been registered range between 185 pounds per square inch and 800 p.s.i. The highest known boxing punch registered 1,300 p.s.I was at the boxer's peak and then dropped down to the normal range. If the 2,150 p.s.i. punch thrown by Drago was in fact real, Rocky would be receiving forces equal to over eighty times normal gravity (80 g's) each time. In other words, one or two 2,150 p.s.i. punches, if it were possible, would kill Rocky instantly (Wayne State Tolerance Curve). However, the Soviet Union was known for using different means of deception during the cold war so this could be just propaganda to make Drago seem superhuman and invincible.

Rocky gets the worst beating of the entire series in this film. However, he doesn't have nearly the extent of facial damage that he received in the first two Rocky's. In Rocky II, his face was literally beaten to a pulp. Here, his injuries are very minor by comparison because most athletes turn to plastic surgery to minimize the look of the injuries to make themselves more presentable and marketable.

When Rocky first arrives in Russia, Paulie can be heard complaining about the conditions in which he will have to live in. He references not being able to watch the Rose Bowl game out here. Even though the Rose Bowl game is not played until New Year's Day and Rocky's fight takes place on Christmas, Paulie most likely meant not being able to watch the game because Russia doesn't air it.

Rocky and his entourage arrive at the Russian airfield in an aircraft that appears to be a Douglas DC-3, an American produced aircraft. In the context of this movie, it would be a Lisunov Li-2, which was a licensed copy of the DC-3 that was mass produced and widely used in the Soviet Union.



Revealing mistakes

After the Creed/Drago match, when there is a montage of newspaper clippings about Rocky deciding to fight Drago, the first clipping if you look closely at the article and read it... you'll notice that the article isn't even about Rocky, but that it is actually about the world series.

License plates on both KGB cars in Krasnogubernsk are not corresponding to the region where they supposed to be registered. (The first letter on one license plate doesn't exist in Russian alphabet.)

When Apollo announces his intention to fight Drago before the press, a montage of newspaper clippings is shown just before this. The print of one of the articles, with photos of both Apollo and Drago, doesn't report the upcoming fight at all but instead is about union-employer negotiations at the Chrysler company.

During the final fight, several shots show a wall perhaps ten rows away from the ring, revealing how small the room was that the fight was shot in.

As Rocky climbs into his Lamborghini Jalpa and "No Easy Way Out" starts playing, the driveway "bricks" can be seen buckling underneath the tires in the close-up of them.



Miscellaneous

During the training montage in Russia there is a part where Drago is sparring and Rocky is chopping down a tree. However, when the tree falls you can hear the background noise of a chainsaw. It is more distinct in the VHS version.

During the training montage, a technician is shown checking a cover on the exercise equipment, revealing some sort of glowing electric capacitors. There is no type of electronic device like this in existence, and no reason to have a cover on it like that.

Despite Rocky getting knocked down and severely beaten by Drago throughout the first round, Adrian seems more concerned when Rocky gets thrown to the canvas in the second round.

Drago was never as monitored or surveyed during his stay in the USA as much as Rocky was during his own stay in the USSR.



Anachronisms

The Soviet Anthem version heard at the match was the 1944-1977 version. It is highly unlikely that it would be played on the time of the event.

Audio/visual unsynchronized

At Paulie's birthday party, he makes a comment to the robot. His mouth is shut before he is done "talking".

During the First 2 Rounds of the Rocky/Drago Fight the USA Announcers are seen on the side of the ring right in front of the Fighters. The Main Commentator is talking during the fight but if you look at the quick shots of the commentator that should be talking his mouth is not moving.



Crew or equipment visible

During the montage, whilst Rocky is driving around reminiscing about the past, there is a clip of Rocky and Apollo jogging in front of a mirror. At the bottom of the mirror you can see a small camera light moving back and forth.

The production's actual camera crew (cameramen and grips) can be seen in several shots during the climactic match between Rocky and Drago.



Errors in geography

In the closing speech, after the Moscow bout, Rocky says: "My son (in America) should be sleeping now..." If it's evening in Moscow then in most of the USA it's early afternoon.

At the end of the fight, Rocky makes his speech, then says "Hello to his kid at home who should be sleeping" And seen in the background of the house is a window that is black due to night time. However, Moscow (where the fight is being fought) is 8 hours ahead of Philadelphia. Thus, even if the fight ends at Midnight Moscow time, it's still 4pm Philadelphia time and even on Christmas Day, the sun is still up at 4pm, And his son would have no reason to have to be in bed sleeping. (Theatrical cut only, as all footage of Robert watching the fight has been cut from the director's cut).

Throughout Rocky's training in the wilds of the USSR he is frequently filmed with the Tetons and the Grand Teton in particular in the background. Only notable because of how identifiable and unique the Teton range is. Given that the film was shot during the Cold War, it would have been very difficult, if not impossible, for a film which is basically about the Cold War and the Russians losing, to be filmed in the USSR.

The Mercedes-Benz's driven by Soviet officials in the USSR are both the US-spec variants of their respective models (the 1977 Benz has four round headlights as opposed to the standard two rectangular headlights the Soviet market got).



Plot holes

Rocky somehow ends up with an incredible tan when he fights Drago, despite having spent months training, completely covered up, in the snow.

In the Director's Cut, Robert Jr. is never mentioned again after Rocky talks with him. If the audience assumes Robert stayed at home, there's no one to babysit him since the robot has been removed from the DC.

Even though tensions are high as it is the Cold War, very few people (if any at all) acknowledge that Rocky should have stopped the fight.



Character error

At the end of the Drago/Rocky Bout... Rocky gives a speech where he says, "Today there are 2 people killing each other but I guess it's better than 20 Million people". The Russian translator however translates this as "It's better than 20 Million Dollars". (Theatrical cut only, as the "dollar" mistake was cut out of the director's cut)

Apollo had forgotten what he learned about underestimating an opponent, especially one he knows nothing about. In the press conference in Rocky II, he attributed his defeat to taking the fight "too lightly," which he did. Here, he makes the exact same mistake, but at a much more tragic cost.

It seems unusually coincidental that the force of Drago's punch recorded on the dynamometer is exactly the reported strength of his average punch (1,850 psi).