Continuity: At the beginning of the film, Casey is cooking popcorn on the stove. When she peels the top off, you see her peel the side away from the handle, and she's using her left hand, but when the shot changes, she's using her right hand, and is pulling from the other side.

Continuity: When Casey is making popcorn, firstly the top of the popcorn that she tears off and places next to the stove changes from being folded in half, to later on laying down flat. Secondly Casey picks up a salt shaker and places it by the stove, but this later disappears.

Revealing: When the killer first stabs Casey, whilst chasing her outside, you can see that as the killer grabs her, some of Drew Barrymore's real hair fall out from under her wig.

Revealing: When the killer surprises Syd after she's come in from outside and locked the door, he tries to stab her with his left hand, misses, and hits the door right next to the chain in closeup. In wide shot (very quick shot) when Syd legs it, look at the killer and you can see he's holding a very badly bent knife in his right hand, nowhere near the chain.

Continuity: When Sydney is talking to Tatum and Stu by the lockers, the combination locks she's standing by are black in a closeup, but when a student runs past in a scream costume, she is by lockers with a pink and a turquoise colour lock.