Plot hole: When Nosferatu is caught in the sunlight towards the end, his reflection can be seen in the tall standing mirror in the corner of the room. This makes no sense because vampires do not cast reflections. Deliberate or not, in the original Bram Stoker novel, there is a scene in which the character Harker is shaving, and is disturbed to see that the Count casts no reflection. There is also a passage that states, "He throws no shadow, he make in the mirror no reflect." Some would argue that the rising of the sun robs him of his powers, giving him the reflection. But his reflection is visible before the rooster starts crowing, before the sun even rises.
Suggested correction: That's all from the book, none of that is established in the film.
Revealing mistake: When Count Orlok has loaded the crates onto the cart, he climbs into the last one and the lid "levitates" into place. This trick is achieved by stop-motion animation, but the cart horses do not hold their position and shatter the illusion - their heads unnaturally jerk about while the lid is in motion.
Revealing mistake: When Hutter is writing his letter to Ellen in Count Orlok's castle, the paper that he is meant to be writing on is blank throughout the scene.
Continuity mistake: When the sailor and captain go below decks, the sailor comes from behind the captain to stand next to him twice between the shots. (00:56:00 - 00:56:35)
Audio problem: In Orlok's dining room, the clock chimes about seven times even though Orlok said minutes ago that it was almost midnight.
Audio problem: In Orlok's dining room, the orchestral sounds of the clock chiming continue after the clock has visibly stopped chiming.
Continuity mistake: When Hutter meets his wife at home early in the film, he runs to embrace her. In the close shot that immediately follows, he is a few steps farther back than he was a second earlier.
Revealing mistake: When Hutter is lying on his bed unconscious after being threatened by Count Orlok, you can see the 'unconscious' Hutter blink.
Continuity mistake: When Ellen dies on her bed at the end of the film, she collapses on the pillow and her head is looking upwards, but in the next shot, her head is now facing left.
Continuity mistake: When we first see the dead ship captain, his eyes are half open. When they find the captain behind the steering wheel a little later on, his eyes are closed.
Continuity mistake: When Ellen has finished reading Hutter's letter on the beach, she crumples it up in her hands, but in the next shot it is whole again.
Visible crew/equipment: When Hutter is sitting on the bed in his room at the inn, a prop or piece of equipment is being moved by a crew member in the lower left corner of the screen.
