Continuity: When the street doors of the London concert hall open to admit Dracula, the orchestra can be heard playing Schubert's "Unfinished Symphony". But in the next shot, an instant later, they are playing the conclusion of the prelude to "Die Meistersinger".
Errors in geography: Dr. Seward's sanitarium is said to be both "near London" and "in Whitby." Whitby, on the Yorkshire coast in northern England, is nowhere near London.
Continuity: After Renfield accidentally cuts his finger, his bed is seen turned down in the long shot. Although Dracula has not had the time to perform the courtesy.
Crew or equipment visible: Pieces of cardboard placed on the lamps in bedrooms, apparently to shield lights for close-ups. It may have been intentional but no one in the cast ever notices.
Factual errors: On main title, Carl Laemmle's studio affiliation is listed as "Presient"
Revealing mistakes: When Renfield is killed, the sound of his body rolling down the steps reveals that they are actually made of wood and not stone.
Continuity: When Dracula is asking if Renfield has kept his trip to Transylvania secret, Renfield's valise jumps from Dracula's hands to the table. This is the result of a cut line.
Factual errors:Joan Standing is wrongly credited as a maid, but she was actually playing the part of Briggs (a nurse). Moon Carroll played the uncredited part as a maid. She's the one who faints when Renfield is laughing very scary.
Crew or equipment visible: When the vampire bat hovers outside Lucy's window and flaps its wings, you can see the wires attached to the bat, pulling it up and down and causing the wings to flap.
Factual errors: During the beginning shots at the castle Dracula, they show shots of bats and armadillos. Armadillos are not native to Europe, only the southern US, Central America and South America. A rat-like animal is also shown near one of the caskets in the crypt. The animal is actually a Virginia opossum.
Revealing mistakes: In the scene where Van Helsing is attempting to catch Dracula's lack of reflection in a mirror, there are visible chalk marks on the floor showing Bela Lugosi where to stand for the shot.
Errors made by characters (possibly deliberate errors by the filmmakers): When Dracula's brides converge on Renfield after he has passed out, Dracula enters and motions them away. As they are walking backwards, one bride steps on another bride's dress causing one bride to "catch" another. It is possible that she may have stepped on her own dress.
Errors made by characters (possibly deliberate errors by the filmmakers): Dr. Seward threatens to have Renfield confined in a "strait-jacket". Although this is probably a translation convention for the American audience rather than an unintentional slip, as a British doctor (and as in Stoker's novel, and the 1977 BBC adaptation) the term he should use is "strait-waistcoat".