After Renton has sex with Diane, he has nothing on his penis, but once he gets kicked out into the hallway, he pulls a condom off.
The Doctor slapping Renton's face has no rings on her hand initially, then she has rings on both hands.
When Mark leaves the money for Spud, it is in the middle of the locker and parallel to the locker walls, but when Spud retrieves it the money is crooked and off-center.
Before Begbie throws the glass the woman sitting across from him is wearing tights that aren't fishnet but after he throws the glass the woman sitting across from him is wearing fishnet tights.
When Renton and Spud are in the restaurant to share a soda with 2 straws, once they finish there's one straw sticking out towards Renton, but as the camera moves between shots of them the straw is either pointed at Spud or is gone altogether.
About 41 minutes in, when Spud and Renton are running down the street, several passers by stop to look at the camera, most notably the two women at the left of the screen and the two men carrying bags near the corner from which they have run.
During the pub brawl seen from above, some guys clearly just do pretend to hit each other.
When Begbie strikes the seated man with the pool cue, he clearly hits the seat. The back of the chair is covered by the man's jacket and the cue hits the chair underneath the jacket.
Towards the end of the film when Begbie gets into a fight with the bloke at the bar just before he slams the bloke's head on the bar you can see that the blokes face and hands are covered in blood before Begbie starts to beat him up.
When Tommy wants to try heroin and presents the folded banknote to Renton (seen from both Renton's and Tommy's point of view), the imagery partly visible on one side of the folded note is not consistent with that on the other side.
When Tommy is bench pressing a weights bar while telling Renton about the snooker club, the weights on the bar are clearly made of plastic but they make a clinking sound as if made from metal.
At the start of the film when Renton is knocked down by the Sierra the sound of the car braking can still be heard after the car has come to a complete stop.
When Renton is in his bedroom being forced off heroin by his parents and the baby is crawling across the roof towards him after Sickboy has made an appearance, there is a close-up shot of Renton cowering against the pillow. The shadow of the camera is visible against his face and the pillow.
When Renton is in bed screaming covering his ears, the shadow of the camera is visible.
When Diane meets Spud lying comatose on the street, a bus passes by in the background. The bus is orange, which is the colour of Glasgow City buses, but the movie is set in Edinburgh where the buses are maroon and cream.
Although the film is set in Edinburgh, the Campsie Fells, situated to the north of Glasgow, 50 miles away, are clearly visible.