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)Hamster
Revealing mistake: At the very end, when Sue is walking towards Carrie's grave site to place flowers on the grave, a car in the distance crosses an intersection backwards, giving away the method used to create the weird walk - playing the film in reverse.
Continuity mistake: Near the end of the film, between the time Carrie finishes her bath after the prom and the time her mother stabs her, the wetness of Carrie's hair changes from shot to shot. When she first puts on her nightgown, her hair is almost dry; later on, about when her mother says, "We'll pray," her hair is very damp; when her mother stabs her, her hair is almost dry again.