Humphrey Bogart initially refused the film and was adamant that appearing in such a mediocre project would damage his career. He also claimed to be greatly insulted that he should be assigned to it. Studio head Jack L. Warner threatened him with suspension, and made several personal entreaties to the actor, claiming that his participation would be vital to the well-being of the studio. He seems to worn the actor down eventually. Production was delayed nearly six weeks until Bogart relented.
The only one of five films pairing Humphrey Bogart and Sydney Greenstreet where Bogart plays the bad guy.
First of two films where Humphrey Bogart plays a wife-killer. The other is Die zwei Mrs. Carrolls (1947). Alexis Smith plays the other woman in both films.
The brooch worn by Kathryn Mason is the same one worn by Ingrid Bergman in her opening scene in Casablanca (1942). Also, a statuette resembling the Maltese Falcon is seen perched on top of a file cabinet at the police homicide bureau.
Jack L. Warner had Joan Crawford, who had just joined Warner Bros. and was looking for her first role at the studio, in mind for the role of Kathryn Mason, and sent the script for the film to her. However, after reading it, Crawford told her agent to tell Warner that "Joan Crawford never dies in her movies, and she never ever loses her man to anyone."