Throughout the film, Count Mora (Bela Lugosi) has an unexplained bullet wound on his temple. In the original script Mora was supposed to have had an incestuous relationship with his daughter Luna and to have committed suicide. After filming began, however, MGM deleted references to the crime (and any remaining references may have been deleted when 20 minutes of footage was removed after the film's preview). Because director Tod Browning's previous film, Monstros (1932), had been a box-office disaster, he was unable to object to any changes made by the studio.
Preview reviews list a running time of 80 minutes, indicating that considerable footage was cut prior to the film's release. This would explain why many credited actors are not seen in the final print.
Large South American bats were imported for the picture. According to a contemporary article in the New York Times, the studio was ordered by government officials to export or destroy the bats after the production. The fate of the bats is not known.
The film was banned in Poland, and censors in Hungary excised the screams, shots of bats, and other gruesome scenes.
Marks one of the first known examples of the "cat scare", a horror film trope in which there is a strong build-up of tension followed by a scare from a harmless cat. This occurs early in the film when Dr. Doskil and Jan are frightened by a cat hiding in a suit of armor.