The film was originally banned in Denmark due to the scene where corpses play cards.
The original script 'Easy Does It', was originally intended as a vehicle for Bob Hope. After the huge success of Abbott and Costello Meet Frankenstein (1948), Universal-International wanted another horror comedy with Bud Abbott and Lou Costello, so the script was rewritten for them. Oddly enough, the role played by Boris Karloff was originally written for a woman.
The only Hollywood film with three of the actors' names in the title.
The role eventually played by Boris Karloff was originally a female character named Madame Switzer in the final shooting script which was then titled, 'Abbott and Costello Meet the Killers'. Five days before shooting, Karloff was hired and the character was changed to a swami.
This was Lenore Aubert's last American movie. She signed a seven year contract with Universal-International and her then husband, sweater king and movie actor Julius Altman, was not getting as many acting jobs as his wife and since the war was over he was willing to move back to Europe. Aubert had fallen madly in love with America, became an American citizen and did not want to leave. Altman insisted that Universal executives let Aubert out of her seven year contract. He had done this when she was under contracts to Goldwyn and RKO too. The latter put him under contract to give him the acting bug so he wouldn't pressure Aubert to break her contracts and go to New York City with him. However this time he was determined. Universal executives reluctantly gave in and asked him to let her do a three picture deal. Universal put her in two movies and looking for a third vehicle for her, decided to let her complete her contract change from a seven year contract to a three picture contract by loaning her out to Columbia Pictures for Barbary Pirate (1949). Universal insisted though that the last movie she make in her contract be for them. And that one is Bud Abbott Lou Costello Meet the Killer Boris Karloff (1949).