The satanic prayer Poelzig chants during the black mass scene consists of phrases in Latin, the most recognizable being "cum grano salis" (with a grain of salt).
Edgar G. Ulmer admitted in an interview that Edgar Allan Poe's story was credited to draw public attention, despite the fact it had nothing to do with the story in the movie.
Censors in Italy, Finland and Austria banned the movie outright, while others required cuts of the more gruesome sequences.
This was Universal's biggest hit of 1934.
The set of the main room in Poelzig's house were built for $1,500.
Among the unconventional elements of this film was the soundtrack. At a time (early 1930s) when movie music was usually limited to the titles and credits, Edgar G. Ulmer had an almost continuous background score throughout the entire film.
Edgar G. Ulmer dubbed Bela Lugosi's voice instructing his servant to "wait here" before accompanying Boris Karloff down to be shown his preserved dead wife.
The ill-fated bus driver is a direct homage to the doorman in Der letzte Mann (1924), on which Edgar G. Ulmer worked as Production Designer.
Director Edgar G. Ulmer, when writing this film, loosely based the villain Hjalmar Poelzig, played by Boris Karloff, on director Fritz Lang. Ulmer knew Lang from the German-Austrian film scene and, though he was a huge admirer of Lang's films, felt Lang to be a sadist as a director.
The only Universal picture until The Wolf Man (1941) to introduce the major characters during the opening credits, and the actors playing them, with brief clips from the movie.