- Hostility on the Set:
- A quarrel broke up the friendship between Boris Karloff and James Whale, who never spoke again. The former partners would only communicate via messages delivered by other cast members.
- During the production, Gloria Stuart was rather dismissive of the British members of the cast, regarding them as "aloof" and "snooty." Indeed, she remarked that Karloff was the most unpleasant of them all, spurring unnecessary rows with Whale which delayed production for hours when Whale refused to return to the set. She would later refer to Karloff as "guileful" and "self-absorbed."
- Method Acting: In a 1988 interview, Gloria Stuart recalled that Boris Karloff ran back and forth across the stage to achieve the desired effect of being out of breath. She asked him, "Can't you just FAKE it?" and he said that wasn't the way he worked.
- Missing Episode: The film was withdrawn from circulation when the remake was released. It was considered to be lost until director Curtis Harrington discovered a printable negative in 1968.
- Uncredited Role: Although uncredited, Jack P. Pierce was responsible for Boris Karloff's elaborate make-up as Morgan. Though the actor employed techniques he previously used as Frankenstein's creature, such as quivering lips and making big eyes to convey emotion or insanity, Pierce's immense talent ensured that the public seldom drew a connection between this role and Karloff's previous performance.
- This is actually mentioned in a title card prior to the credits which states: "Karloff, the mad butler in this production, is the same Karloff who created the part of the mechanical monster in "Frankenstein". We explain this to settle all disputes in advance, even though such disputes are a tribute to his great versatility."
Trivia / The Old Dark House (1932)