•While not exactly a mess-up, when Stu says, "It takes a man to do something like that", he's not exactly right. Randy countered Tatum's Basic Instinct reference ("The killer could have easily been a female; 'Basic Instinct'?") by saying that that was an ice pick, and not the same thing. Apparently, Randy never saw the original Friday The 13th, where, as you know from the first scene in SCREAM (When Casey answers her second question wrong), the killer was a female : Jason's mother.

•In the scene where Sidney is attacked for the first time, the ambulance she is sitting in is a Bayshore ambulance NOT a Woodsboro ambulance. But they may have intended it to be from the neighboring town (we dont know how big Woodsboro is) so this might not actually be a 'mess-up'.

•Also, when Sid is attacked in the bathroom, she leaves her backpack but when her and Tatum are walking home, she has it. Weird...bad editing I suppose. But someone also could have gotten it for her.

•The sheriffs cigarette goes from long, to short, back to long, and then to short when he steps on it.

•There are numerous instances of Ghostface wiping the blood off of his knife after it was already clean -- look at Billy's first death scene. Ghostface wipes the knife, displays the knife to Sidney, and then wipes it again. It is much more obvious in the letterboxed version.

•The first time Randy does his "horror movie rules" speech is different then when it is broadcast to the news van. The second time omits "Jesus Christ!", and Stu's "Have an aneurysm" line.

•When Tatum and Ghostface were in the garage together, Tatum tried to open the door that leads back to the house. It was locked. Then after she had been killed, Ghostface went in through the door and it wasn't locked, and they never showed him unlock it.

•When Tatum throws the beer bottles at Ghostface his costume is covered in beer and foam. When she flips him the costume is mysteriously dry.

•When Tatum tries to go out the "doggy door", in one shot she is past her chest in the door, and in another her chest is still inside.

•After Tatum lunges for the doggy-door in the garage and starts flailing to get through it, we get to see her from the outside. On the left side of her body (where her arm is cut), blood is smeared on the outside of the garage door. But as the camera switches between shots the blood stain magically disappears and then reappears, and continues this throughout the scene. It is very noticeable in the letterbox format.

•Garage doors have "shut off sensors" that automatically shut down the if something is in the way of it opening/closing. Obviously, the one at Stu's house needs to be repaired!

Tatum wasn't in the way of the garage until after she was already crushed up there, so even if it had stopped the garage wouldn't have gone back down, she would have stayed up there and she would have choked to death or he would have killed her some other way.

•Could a small guy like Stu or Billy have actually lifted Kenny (the cameraman) onto the top of the news van? I just dont think so=)

Billy or Stu could've easily lifted the camera guy on to the van. My freind Stu (No Pun intended) is skinny like him and can lift 306. Besides Killers are capable of a lot of things.

•Reversing a vehicle, and then stopping, would not make a body on top fall forward, as Kenny the camera man did on top of the news van.

About the body flying off the top of the van. Have you ever reversed a van with a dead limp body on top???

•Sidney saw Randy almost being attacked while she was in the news van with Kenny. However, a few minutes later when Sidney is confronted by Stu and Randy, she locks both of them out because she is confused and doesn't know which one is the killer. A moment of thought would have saved her a lot of grief -- she would have known that Stu was the killer-and could have shot him (he was the only one left; she thought Billy was dead). She also said on the police radio that she was at Stu Macher's house, and "He's going to kill me!". That sentence is up for debate -- she could have meant "Ghostface" is trying to kill her, or she could have meant that Stu was going to kill her.

Sid really doesn't have time to remember what happened earlier. Think about it: if you were attacked continually, saw your boyfriend "murdered" right after losing your virginity to him, seeing your best friend hanging from a garage door and seeing the camera man get his throat sliced open, I highly doubt you'd be remembering what was on a TV. As for the "he's going to kill me", she didn't mean stu, she probably just assumes it's guy, as anyone would have.

•Near the end when Stu drags out Sidneys Father in the kitchen, Stu puts the white voice box FIRST and then the black phone in the fathers jacket pocket, so the black phone is in the BACK. And then when Stu pushes him to the kitchen floor, the voice changer box starts to fall out and is really visable in his pocket. Then the next scene showing the father on the floor occurs, the phone and voice box are clearly the wrong way round and shoved back neatly into his pocket! This was spotted by Gareth Peddie.

•These are the most obvious mess-ups out of them all. In two instances the looping (after shooting dialogue insertion) seems to not match the actors on screen : once when Sidney sees Dewey coming out of the house, she looks like she is saying "No!" instead of "Dewey!", and again when Gale tells Kenny she will "Be right back", it looks as if she says "Keep watching!".

•If Stu and Billy really went through all that they did as "Ghostface", including the shattered beer bottles, crotch hits, punches, and doors in the face, why didn't Billy or Stu have any bruises or abrasions until the very end when they started to do it to them themselves?

•In the movie, when Gale and Dewey come in to check the party, the room that everyone is watching TV in is directly to the left of the front door. When Sid and Kenny are watching the tape, it shows Ghostface leaving the house through the front door, which was directly to the right of the room. And then, at the very end of the movie, when Sid kills Stu and also when Billy is trying to find Sid, the room with the TV is down the hall and to the right.
This was pointed out to me by Kym