Revealing mistakes: When Rachel is searching the Internet for information, the address in the browser points to a file stored on the desktop of a Windows 98 machine. C:\WIN98\Desktop\....etc...
Continuity: Near the end of the first scene between Noah and Rachel, Noah begins to eat an apple. He is clearly chewing while she is speaking but, without appearing to swallow, has an apple-free mouth when he replies. While Rachel speaks, he is once again chewing, without apparently having taken another bite.
Continuity: The way Aidan's tie is tied during the wake, changes between shots (the stripes move around at the knot).
Crew or equipment visible: After watching the Samara medical video in the Morgan home, Rachel chases Richard Morgan to the stairs and the lighthouse illuminates a crew member's shadow on the wall. Richard is visible at the top of the stairs.
Continuity: When Aiden is drawing in the car with Noah, his clipboard changes color from blue to green.
Factual errors: When Rachel is looking through the newspapers for what time all of the teens died, she sees a time of 10:00 p.m. in one of the papers. According to Associated Press style, it should have read 10 p.m.
Continuity: When the horse rips loose on the ferry, it rips the rope from the wall without breaking the rope. In several subsequent shots, the rope is torn apart.
Continuity: When Noah is at the supermarket buying cigarettes, he pulls out of his pocket a bunch of junk such as coins, trash, and an old pack of cigarettes and dumps it on the counter. In the next shot of the counter, all the junk is gone except for a coin, and the old pack of cigarettes.
Continuity: When Rachel lifts Samara's body out of the water, her hand is covered by Samara's hair. In the next shot, there are only a few strands of hair over her hand.
Crew or equipment visible: When Noah breaks into the mental institution's record room and is looking through Anna's files, there is an arm with a blue sleeve to his right, even though he is alone.
Audio/visual unsynchronized: In one scene, there is a shot of a small clock ticking, but the hand is moving in a smooth motion. The make and model of the small clock does not tick, it is perfectly silent.
Incorrectly regarded as goofs: As Rachel is driving to try to warn Noah, she has her cell phone in her right hand. In the next shot, she has both hands on the wheel. She actually drops the phone to take better control of the wheel to avoid traffic.
Continuity: When Anna is coming up behind Samara just before putting the trash bag over her head, we see both hands at the same time and there is no trash bag in sight
Continuity: At the funeral, when Aidan is in Katie's room, the closet door opens and shuts repeatedly between shots
Continuity: When Noah chops a hole in the floor with the axe, he removes a circle of wood approximately 4 feet in diameter. In the next shot, shot from below the floor looking up, the whole is easily over 15 feet wide.
Revealing mistakes: In the group photo of Anna Morgan with the old women, the shadows on her face reveal that her image has been artificially added to the picture.
Continuity: On the ferry the horse runs - and then falls over - along the center line of the ferry, but as we see the horse fall into the water this happens on the left side of the ferry.
Audio/visual unsynchronized: On the ferry, when the people gather at the stern to see the horse that fell overboard, a little girl next to Rachel screams, but the sound of the scream continues even after the girl stops and breaths in.
Continuity: When Noah and Rachel uncover the well, they drop a rock to see how deep it is, and we hear it drop on the bottom of concrete. When Rachel falls into the well, she falls into water, not on concrete.
Continuity: When Rachel falls into the well, the torch light reaches the end of the well, meanwhile earlier on Noah says that they don't know how deep it is, as the light won't reach the bottom, and when they throw a rock into the well, it takes far too long to reach the bottom for how far Rachel falls into the water.
Continuity: When the father of Samara dies by electrocution in the bath, at first it shows blood, and then when you return to him dying, there is no blood in the bath.
Continuity: Mr Morgan tells Rachel to leave his house, he opens the door and you can see that the day is very sunny, when he closes the door, it's full of fog and very cloudy.
Continuity: When Rachel is researching Anna Morgan and Moesko Island in the newspaper archives, she is unconsciously scribbling on a picture of Anna. Between shots, the scribble changes shape from fanning outward to completely vertical.
Continuity: The level of the water in the well is not continuous. When Rachel is standing in the water it only comes slightly above her waist but if she were to fall from the height she did and the water was that shallow, she would have hit the bottom.
Continuity: After Noah watches the video and the phone rings the position of the wire underneath the phone changes in different shots even though nobody touches it.
Continuity: In the shot of the horse falling off the ferry, the ferry's name "Quinault Seattle WA" is seen on it's 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.
Factual errors: When Rachel is holding the tape at sunset just before watching it, the shadows and red light move across her and the room downward; however shadows cast by a setting sun would move upward not downward.