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)
Suggested correction: When you watch the movie leading up to that event, it's obvious that Norma is a tomboy, and is always wearing a ball cap and wearing her hair like that. It's who she is and perhaps decided after her hair was done that it didn't feel right and decided to go back to her look.
Continuity mistake: When Mrs. Baylock pushes Kathy from the hospital window, we hear the sound of breaking glass. However, when she plunges into the ambulance, there is no glass whatsoever, nor do we see any when she is falling. (01:24:30)
Continuity mistake: When Frank Hallet first enters Rynn's house, he leaves muddy footprints all over the floor. The footprints are gone in later shots.
Continuity mistake: When Christella is slapped by the possessed Ike, her pose changes between shots.
Continuity mistake: When Brooke Shields yells "Mommy said that you had to come home right this instant", there's a long lock of hair in front of her left shoulder, which disappears at the cut. (00:06:20)