Audio problem: When Sidney comes running to the house and she sees Dewey come out with the knife in his back she screams "Dewey!" but her mouth says "no!"

Revealing: As Drew Barrymore is running from the killer outside he stabs her.  If you look closely it is very easy to tell it is a rubber knife, because you see it bend off of her.

Continuity: When Ghostface is trying to kill Tatum in the garage, she tries to go through the doggie door. From the outside shot, she is out of the door from her arms and up. From the inside shot, she is out of the door from her hips and up.

Deliberate "mistake": When Randy is explaining the "rules" and he is standing beside the television the batteries fall out of the remote yet he still manages to change the TV over.

Audio problem: When Gale is talking to Kenny the cameraman before she goes off to investigate the abandoned car with Dewey her face is in a close up. She can be clearly heard uttering the forbidden phrase "I'll be right back." However her mouth can clearly be seen saying "keep watching."