Continuity mistake: In the last scene to be filmed, with Orlock and Gretta, the candles on the dresser are alternately lit and then out, as Orlock's reflection is visible then not in the mirror.
Continuity mistake: When the girl discovers her bed all bloody, she touches the blood and her hands get bloody. She grabs a book and starts flipping the pages, but if you watch closely ,you can observe that her hands are clean, there is no blood.
Continuity mistake: In the close up of Thorne dropping his keys in a dish near the beginning of the movie, his keys are for a Dodge vehicle, but he drives a Cheverolet Sedan.
Continuity mistake: When Marci escapes from the web in the elevator shaft, she closes the door on the spider chasing her. In that sequence, the door closes automatically; in other scenes, the door opens and closes manually.
Continuity mistake: In one scene we see a police officer investigating his colleague's disappearance. In the long shot we see him walking towards the other police car and it can be seen that the number plate is a fake. A fake paper number plate has been placed over the original number plate. When the wind blows you can see the side of the paper blowing in the wind. (01:16:05)
Continuity mistake: In the first movie, it took quite some time (days if not weeks) for Tomie to regenerate back her full body. In this film, it seems to happen in mere hours after her head is placed into the tank for observation.