Humphrey Bogart said of this film: "This is one of the pictures that made me march in to [Warner Bros. studio chief Jack L. Warner] and ask for more money again. You can't believe what this one was like. I had a part that somebody like Bela Lugosi or Boris Karloff should have played. I was this doctor, brought back to life, and the only thing that nourished this poor bastard was blood. If it had been Jack Warner's blood or [Harry Warner's] or [Sam Warner's] maybe I wouldn't have minded as much. The trouble was, they were drinking mine and I was making this rotten movie."
Various sources have reported Humphrey Bogart reacting with anger when asked to make the film. He was alleged to have stormed into Jack L. Warner's office, thrown his script across his desk, and demanded more money for making such rubbish.
The Return of Dr. X was the directorial debut of former actor, screenwriter and dialogue director Vincent Sherman (1906--2006) who went on to direct dozens of Warner Bros. films, among them Old Acquaintance (1943) and The Hasty Heart (1949), and numerous TV programs for that studio and for others until his retirement in the 1980s.