Goofs

In the scene where Marcy is attacked by the dog, the camera shows her trying to get into the shed, and then cuts to the dog. When the camera shows her being taken down by the dog, she is wearing blue jeans. This is because the dog used was so vicious, the actors could not be around it, so a guy had to step in with protective layering on his arm to be attacked.

The bedclothes for Marcy and Jeff's bed remains consistent for the duration of the movie, save for the light-colored bed-sheet that appears during the sex scene between Marcy and Paul, that covers Marcy's behind, and then is not seen again.

When Bert is being chased in the woods he puts his blood on a tree as a diversion; however, there is already blood on the tree which is probably from a previous take.

After Bert coughs up blood next to the Blazer, he wipes his face, and he still has blood on his chin, but when he gets up and yells at Jeff to hurry up, it's gone.

The rims on the Chevrolet Blazer K-5 change.

The water supply in the cabin was connected directly to the reservoir. Water from reservoirs cannot be used for domestic purposes without a large treatment plant to remove minerals, kill bacteria and perform general filtering. Using a reservoir as a water supply for a remote cabin is highly improbable.

Deputy Olson is seen partying and drinking alcohol with underage girls in one scene, even though in real life, he would have been suspended from the police force for such a thing.

Justin (Grim) is clearly seen tying his dog to a tree when he meets the main characters at the bonfire. It was thought that when he leaves he just calls his dog and walks away, however you can still see him crouching by his tied up dog as the camera pans away.

Though the scenery dictates fall, and the characters say that they had just finished finals, they mean that they had just finished their Fall semester finals, not their end of year or spring semester finals.

When Marcy starts having sex with Paul, despite the fact that she throws him down on the bed from an upright position, when she falls on him there is a bed-sheet covering her ass. It's obvious that the sheet has somehow been stuck to her body, as it would have fallen off otherwise. (See trivia.)

The cabin has a working fireplace, but no sign of a chimney on the roof.

The main water pipe shown connected to the cabin is much wider than what would actually be used to supply a small cabin. Or even a regular-sized house, for that matter.

The store owner says that the total of the kids purchases comes to "$56.00 even" and Jeff actually hands the owner $57.00- two twenties, a ten, a five, and two singles.

When Jeff discovers the bathroom in its final, bloody state. There is blood in places that Marcy (the source of the blood) would never have touched, such as high up on the column of the bathroom sink.

Just after Burt is caught stealing the Snickers bar, he climbs into the back of the truck and mumbles that he should burn the store down but his lips only appear to move as the truck takes off.

There is a cameraman visible in rear view mirror at the beginning of the film as the characters begin their trip out of town on the way to the cabin. Although this should normally qualify as a goof, this scene was left in by director Eli Roth on purpose. See also trivia section.

When the camera follows the water line from the dead hermit's body in the reservoir to the cabin, a small shrub bends over (seemingly) all by itself. Obviously it has been run down by the camera.

Paul tells Marcy that he's going to get Jeff so that the three of them can walk out of the woods together. But when Paul races back to the cabin after his short journey, he runs in from the left side of the cabin. Paul knew that Jeff went off to the right when he ran away.

When the patrol officer first arrives at the house, he explains that almost everyone does not have a telephone, only a radio, including himself. However, at the end of the conversation, he confirms that the way to reach him was by dialing 9-1-1.

When Marcy is washing her face in the bathroom, and turns around to see the red marks on her back in the mirror, the shadow of the boom mic is visible just over her shoulder (in the mirror).