Anachronisms: The Topps baseball card in Gordie's brother's room was not available until after the film was set.
Continuity: Teddy's hair changes in every shot after being dunked in the swamp. The strap to his bag disappears and reappears as well.
Continuity: During the train chase, the sky goes back and forth from cloudy to clear.
Revealing mistakes: When Gordie looks at the newspaper article at the beginning, the first paragraph of the article is about the stabbing, but the second column is clearly from another story.
Anachronisms: The water pump shown at the end of the movie is a Waterous. The style was not available until the 1980s.
Continuity: When Chris comforts Teddy after Milo Presman insults him, Chris takes his hand off Teddy's shoulder in one shot, it then reappears on his shoulder in the next shot.
Continuity: In the swamp, Teddy's glasses go from being on his face, to being folded in his hand, to being back onto his face, and then we see him actually removing the glasses and folding them into his hand.
Continuity: Amount of blueberries and sauce on Lardass Davey Hogan's face before he vomits.
Anachronisms: 1980s cars visible in the background of the junkyard.
Anachronisms: Aluminum cans in the general store.
Crew or equipment visible: The camera tripod can be seen in Teddy's glasses when Teddy and Chris are arguing on the railroad tracks.
Boom mic visible: When Ace is playing pool with Billy, the boom mic bobs into view, near the light.
Boom mic visible: When Gordie goes into the store and the clerk talks to him, you can cleary see the boom mic bobbing into view and then being taken away.
Anachronisms: When Gordie visits the delicatessen for hamburger, the grocer pulls waxed paper from a box with a 1980s Crown Zellerbach logo on it.
Revealing mistakes: At the beginning, in the wide shot of Gordon Lachance's car, the man behind the wheel is an obvious stunt driver. So is the man driving Ace's car during the game of chicken in wide shots.
Incorrectly regarded as goofs: Gordie is not looking for his hat in his brother's room, he only reminisces about it there. It wasn't in that room, so it's not an error for him to be wearing it later without taking it from the room.
Incorrectly regarded as goofs: The narrator does not save his work before appearing to shut off his word processor, but that's okay, because in fact he only switches off the monitor, leaving the machine running and his work intact. Also, the shot of the narrator writing has him seated at his desk; when he turns off the word processor, he is standing, studying his work. It is reasonable to presume that a brief moment went by between the shots, and he could easily have saved the work then.
Crew or equipment visible: In the first train dodge scene, after Teddy and Chris make up, as Verne walks off back onto the train track you can see his wireless mike drop down his left leg and flop near his ankle.
Anachronisms: The military jungle boots teddy is wearing were not available in 1959.
Crew or equipment visible: After Ace takes Gordie's cap, the reflection of half of a member of the crew can clearly be seen waving their arm in one of the store windows behind Chris and Gordie.
Continuity: When Gordie and Chris discuss Gordie's size, their positions change.
Continuity: When Ace and the others are playing chicken, the position of the logs off the truck change.
Continuity: When Lardass is confronted, and is half laying on the table, the man's hands change position.
Continuity: When Gordie and the others get back to town and are saying good-bye, the positions of Gordie and Chris change.
Continuity: When the boys are seen walking into the leech pond, they all fall in. We see Vern and Teddy go into the water, and when they come back up to surface, we can see Chris and Gordie on the surface already on the right side of the screen. However, in the very next shot, Gordie and Chris come to surface again.
Continuity: When the boys are at the leech pond Chris is seeing how deep the water is with a stick. The stick changes in size.
Miscellaneous: Leeches appear on Chris' back between shots when the boys are covered in them.
Audio/visual unsynchronized: When Vern climbs into the treehouse, his lips are clearly not matching what we hear.
Continuity: Teddy's left ear (which his father almost burned off) in the treehouse scene is very clearly burned. Throughout the movie, however, it varies in how it looks, in the train tracks scene it looks perfectly normal.
Anachronisms: When Gordie is in the delicatessen there is a bottle of Soft Soap in the background that was not available in 1959.
Continuity: When Ace is racing against his friends in the car, it clearly shows that he has blond hair, but when it shows the back view of his head, he has brown hair.
Continuity: When the boys are crossing the bridge, and Gordie is trying to help Vern to his feet there is a very brief cutaway showing that the oncoming train is only the engine and one car. The previous shot, and the later one once it passes, all show it to have several cars.
Continuity: When confronted by Ace's gang, Gordie shoots the pistol into the air, and then points it at Ace and pulls back the hammer. The pistol is a Colt 1911 and is an automatic, which means the hammer would have already been cocked after the first shot.
Continuity: When the boys are sitting by the fire cooking hamburgers and Vern's falls off his stick, it clearly falls apart. When he picks it back up with his stick, it is in one piece.
Audio/visual unsynchronized: When Vern is first coming into the tree house and is coming through the trap door he is clearly heard saying "You guys are never gonna believe this...”, but his mouth is saying the previous lines "Oh, man, oh, man".
Continuity: In the clubhouse at the beginning of the movie, Chris has a pack of cigarettes tucked into his sleeve. It disappears and reappears throughout the scene.
Continuity: When Gordie shoots the garbage cans and runs off, he's still running when they get around the corner and he's not holding the gun anymore. He wouldn't have dropped it because it's in later scenes, and he didn't have enough time to put it in his backpack or give it to Chris because they were trying to get far away from the back of the diner.
Continuity: When the boys get dunked in the swamp, Teddy takes his glasses off, but then while they're thrashing around in the water, both hands are clearly empty. Then, when they get out, he has his glasses in his hand again.
Revealing mistakes: In the train scene, River Phoenix's voice has suddenly changed and he looks older. This scene was obviously shot last, and he has started going through puberty. But in terms of movie time, he has gone through puberty in two days.
Continuity: All four guys are in the junk-yard and they are all about to toss their coins to see who goes to get the food. When Teddy throws his coin in the air he is wearing no dog tag necklace but when he catches the coin he is suddenly wearing the dog tag necklace.
Continuity: Gordie's hair constantly changes throughout the film from floppy to gelled, i.e. in the scene on the trestle over the water he yells, "Train!" and his hair appears to be quite dry, without a parting. In the next short scene around the campfire, it looks perfectly combed and gelled. He can not have borrowed Vern's comb, since Vern lost it on the train bridge.
Factual errors: In the scene where Gordie goes into Denny's room looking for his canteen, there is a pennant of Michigan State University on the wall. Michigan State wasn't called Michigan State until 1964.
Boom mic visible: Immediately before the boys start to cross the bridge.
Revealing mistakes: In the "barforama" scene, the jets of vomit do not quite seem to come from out of the mouths of the actors.
Continuity: When Gordie is in the store buying food for everybody one of the first things he does is put 4 Coca-Cola bottles on the counter. He then buys bread and meat which he probably put in his bag on his walk back. But it never shows him with the drinks again and he could not have put them in his bag because the tops were already off.
Crew or equipment visible: During the "barf-o-rama" scene, the two twin brothers barf on each other. As the second brother barfs, the other brother turns his head and you can see the white tubing of the barf mechanism on or around his left ear.
Revealing mistakes: Chris says his pistol is a .45 but when he first pulls it out of his pack the barrel is clearly much smaller revealing it to probably be a prop gun.
Revealing mistakes: When Chris and Teddy are arguing in the train scene in the beginning Chris left cheek is dirty, possibly from the scene where he had been pressed to the pavement. But then his right cheek should be dirty.