Continuity mistake: After Noah is killed by Samara, Rachel comes in. She steps up to the chair Noah sits in, looking away from her. She rotates the chair counterclockwise to look at him. We don't see his face yet. We do see it near the end when Rachel has a flashback. For a split second, Noah's face is revealed in the chair now rotating clockwise. It should have been turning the other way around. (01:43:40 - 01:46:05)
Continuity mistake: In the extra/cut scenes included on the DVD, there is one where Rachel is in Katie's room snooping around. She goes over to the cabinet that has the TV on it and opens the top drawer, rummaging through it. After looking, she closes the BOTTOM drawer even though she was looking through the top one in the previous shot.
Continuity mistake: When Rachel lifts Samara out of the water in the well, Samara's hair changes position from shot to shot. First there is no hair on her face at all, then there's some draped across her neck and down the side of her face (which Rachel moves), and finally when Samara "decomposes", the hair across her neck is gone as well. (01:33:00)
Continuity mistake: Rachel goes to the lodge reception and the clerk points out the tape collection to her. She turns and is drawn to The Tape in the centre of the shelf. It is lying sloping up to the left, label spine outwards, spools on the left. When Rachel picks it up to drop it into her bag, it is spools to the right, label spine inwards.
Continuity mistake: In the shot of the horse jumping off the ferry, the ferry's name "Quinault Seattle WA" is seen on its side. Rachel looks down at the horse in the water from the same place it jumped, but the appearance of the ferry's name is now different, namely the position of the two words "Seattle" and "Quinault" are now flush with each other when they were not before. (00:55:40)
Continuity mistake: In the first scene in Rachel's apartment Noah bites into an apple. First we hear him say 'ok' while he is still chewing but it doesn't sound as if there is something in his mouth, then he goes on talking after swallowing down everything, and finally we see him from behind, busily chewing again without having taken another bite. (00:29:30)NancyFelix
Continuity mistake: The scene where Aidan is waiting for his mother in the classroom starts with a close-up of his hand drawing a sun. From the way the rays are arranged we can tell that it's not the same drawing that's used in the later shots. Similarly, the picture his mother takes out of the folder later is not the same she is looking at when the camera angle changes. Also the way she holds it is different. (00:07:20 - 00:09:05)NancyFelix
Continuity mistake: When Rachel enters the reception at Shelter Mountain Inn the caretaker asks her to pick a card from a deck. She picks the nine of diamonds, but when she gives it back to the guy you get a blurred glimpse of the card, and it is a four of something. (That she finally agrees that the seven of spades is the right one is probably because she gets tired of the game.) (00:21:15)NancyFelix
Continuity mistake: After breaking into the records room, Noah is looking at Samara's pictures or photo negatives, holding them up to the light, the shot of him show his fingers covering some of the first picture, but the next shot from his point of view the whole picture is visible and his fingers cannot be seen. (01:04:25)