Continuity mistake: The costume of Ghostface/Father Death is stuffed inside the plastic bag in two different ways in the shots when Sheriff Burke is checking it out - look at the bits coming out in the close-up. (00:35:05)
Continuity mistake: Billy holds Sidney in his arms after the attempt at her life downstairs. She clings to him and pulls at his jacket, that is unperturbed in the close-ups on Skeet Ulrich. (00:29:55)
Continuity mistake: When Sidney manages to kick Ghostface away after he has almost stabbed her behind the front door of her house, she sets up the kick shouting "no" and shielding herself with her left arm, but in the shot of the actual kick the stuntwoman's left arm is on the ground. (00:28:55)
Continuity mistake: In class, the teacher tells Sidney "It appears to be your turn." One of her classmates, a girl with a grunge shirt, turns around to look at her, but in the next shot she's looking ahead. (00:18:55)
Audio problem: Casey's dad tells his wife to call the police. Meanwhile, he runs upstairs yelling "Casey, are you upstairs?" He reacts to his wife's line turning towards her before she says "Casey, baby?" (the mother does whisper "My God" a moment before he stops and turns too, but it was a whisper, good luck hearing that when he was rushing upstairs and shouting his line). (00:12:10)
Continuity mistake: In the close-up when she clutches Ghostface's mask, Casey's hand is significantly bloodier than in the rest of the scene and the sleeve that was creased down straightened itself, with a different bloodstain. (00:11:35)
Continuity mistake: When Casey pops up to peek at the window and is face to face with the killer, she shakes with fear reacting very naturally, but in its close-up her left arm is sticking out perfectly steady and firm in an incredibly unnatural position, blatantly there holding still just so the killer can grab it. (00:10:20)
Continuity mistake: When Casey peeks at the letter opener on top of the TV, her hair is on top of the cordless phone; in the shots from the side, before and after, her wig is pressed against her cheek and ear by the phone itself. (00:08:40)
Continuity mistake: There's a close-up of Drew Barrymore's foot when she unplugs the lights when the killer is starting his trivia. She tosses the cable and plug blindly behind her. In the next shot, the plug is closer to her foot and the shadow resulting from the change in light is also different. (00:06:25)
Continuity mistake: If you look at the close-up of Casey's hands when she locks the door, you can see her left arm in frame, but in the next shot she is holding the phone to her ear with it. Later on there's a mistake even more blatant as she unlocks momentarily the patio door to check on Steve; in close-up she uses her right hand, the killer reprimands her for the stupidity of the move, and she pulls back her left hand, as the right hand is once again the phone hand. (00:02:55 - 00:05:45)
Continuity mistake: At the police station, Billy looks back with anger at Sidney after the sheriff tells him that they have to detain him until the phone records come in. The sheriff is looking at him with his arms crossed, but in the close up on Skeet Ulrich the sheriff's got his hands on his thighs. (00:34:10)
Other mistake: When Stu brings Sidney's dad out in the kitchen, you can see behind him a September 1996 calendar. Earlier in the movie, the scenes inside Principal Arthur Himbry's office do show a September calendar, which is obviously the intent of the movie, but it's a September 1997 calendar.
Character mistake: When they are surprised by Gale, Billy angrily says to Stu "Man, I thought she was dead." To which Stu replies "She looked dead, man. Still does." However, Stu didn't have time to check on Gale, since she crashed the vehicle moments before Sidney is attacked by a Ghostface that had to be Stu himself (since he does the quick clothes switch coming from the car).
Visible crew/equipment: When Drew Barrymore runs away after the killer just called her 'blondie', there's nobody behind her character, and yet a new shadow is cast on the wall to the left when the camera follows her around the corner to lock the front door. (00:03:50)
Other mistake: Two police officers drag Billy Loomis out from the sheriff office across the station; the younger officer stares into the camera right before it cuts away. (00:34:40)
Character mistake: Sidney asks on the porch why Cotton couldn't prove that he was having an affair with her mom. Tatum's answer is "Well, you can't prove a rumor. That's why it's a rumor." That's quite the preposterous answer, especially since the point she wants to make is that it was not in fact 'just' a rumor.
Suggested correction: Tatum isn't trying to argue with Sidney. Tatum agrees that she doesn't know the truth about her mother's infidelity and certainly can't prove anything. Rather, what Tatum is trying to tell her - gently and somewhat indirectly - is that she believes the rumors, which is distinct from knowing the facts.
