Continuity mistake: When Norma and Helen are in the salon, and they are talking about Carrie going to the prom with Tommy, Norma is getting a fancy hairdo done for the prom. But in the next gym scene, she has her plain braids and a cap on. (00:48:20)
Character mistake: During the opening scene, the girls are playing volleyball. The score was announced, and game point was announced. When the ball is served it comes to Sue, she hits the ball twice, in succession, which is against the rules, she is on the same team as Carrie. This should have ended the game, but the point continues, the team they are both on gets the ball over the net, then it comes back, right at Carrie, she does not hit the ball, then the game is over, and a few of her teammates can be heard saying various insults about her inability to play the game and so forth. If they would have been playing by the rules, the ball should have never even came to Carrie.
Visible crew/equipment: As the house is crumbling in on itself in one of the last scenes, there are a couple of shots of the ceiling being pushed in by some 'unseen force'. If you look closely as the last bit is falling, you can catch a glimpse of a hand and black sleeve pushing it in.