During the opening sequence with Renfield in the coach, we see a shot of the setting sun against a darkening sky, but when the camera cuts back to the coach, the sky is still bright blue and clearly daytime.
When Count Dracula is spinning Mina around in front of the mirror, he is holding her by one arm and one leg, both stretched out towards him. In the mirror, her legs are closer to each other than before.
In the funeral scene between Jonathan and Lucy, Lucy is putting her hands on Jonathans chest. In the next shot from the other side she has her hands on his shoulders and the next shot her hands are on his chest again.
When Dracula appears to Renfield in the sanitarium, Renfield sits up with the covers still draped over him, in the next shot, the covers are completely off.
When Renfield begins to sit down in the chair at Dracula's mansion, he is seen setting his briefcase down, however the briefcase is open and the papers are arranged on the desk in the next shot, without any time for Renfield to have taken them out.
In 19th century currency in Transilvanya was mark, not kopeks like women sell cross to Thomas.
When Dracula arrives in London, he tells the woman at the opera she will receive no tip. The UK do not provide tips in their economy.-------People in the UK do give tips, but it is done at the customer's discretion, and is given for good service, not as an expected payment. Tips are most commonly given in a restaurant or taxi, but not in a bar or theatre.
When Sykes hears Lucy's voice begging to be let out of her coffin, he accidentally moves the "stone" lid, showing it to have no weight.
When Dracula flies down from Renfield's cell window, the black cable on the stuntman's back is visible.
During the dance scene with the big mirror, we see Dracula spinning Mina around. The camera then pans slowly towards the mirror, and we see Mina spinning around midair. She spins at the same speed as in the part of the shot that includes Dracula. However, we can see in the background the white-gloved hands of the conductor, moving up and down at a very slow rate. This suggests that the midair-Mina was actually spinning a lot faster and the scene was slowed down.
Towards the end when Jonathan and Dr. Seward are pushing against the door to try and break it down, the entire wall which is supposed to be made of stone, moves with every strike against the door.
When Dracula visits Renfield in the sanitarium, he pulls apart the metal bars on Renfield's window to have him crawl out. When Dracula let's go of the bars, it is obvious that they are made of rubber.
In the end credits, the ship's captain is listed, yet the character does not appear on-screen, presumably was cut from the final edit.
As Dracula lowers himself from the roof of the asylum to release Renfield, he casts a shadow on the back of the set.
The dummy Dracula used for the door-slamming / falling from the ceiling gag is ill-proportioned, and its arm bounces in a rubbery fashion as it hits the floor.
The two vampiresses in bed with Renfield are clearly barefoot, yet when they lumber out of the room, the soundtrack suggests they are wearing heavy shoes.
When Dracula has Harker by the neck in the attic scene, his mouth movements don't match with what he's saying.
During the climax when Dracula throws a wooden beam towards Harker and Seward, a crew members hand can be briefly seen on the right hand chucking the beam towards Seward.