Humphrey Bogart disparagingly referred to this movie as "The Amazing Doctor Clitoris".
Ronald Reagan's voice can be heard as a radio announcer, a job that Reagan held before he started as a film actor.
Producer Robert Lord favored Ronald Colman in the title role but was overruled by studio boss Jack L. Warner, who cast studio contractee Edward G. Robinson. After director Anatole Litvak was assigned to the project, Lord's role shifted from producer to associate producer.
Humphrey Bogart later said that the role of "Rocks" Valentine was one of his least favorites.
Cary Grant was considered for the role of Dr Clitterhouse. At one point, Bette Davis was considered.
Nearly all of the characters' names are changed from the original play on which the film is based.
After the New York production, the studio had some difficulty obtaining the movie rights to the play because Barre Lyndon retained control of the movie rights and placed the play on the open market.
Carl Laemmle Jr., Paramount and MGM bid for the rights to the play. Laemmle bought them for over $50,000. He then turned them around and sold them to Warners in return for the loan of Paul Muni for "The Hunchback of Notre Dame", a film that never got made.
Irving Rapper was originally assigned to the film as dialogue director, but was replaced by Jo Graham.
"The Screen Guild Theater" broadcast a 30 minute radio adaptation of the movie on November 2, 1941 with Edward G. Robinson and Humphrey Bogart reprising their film roles.
"The Screen Guild Theater" broadcast a 30 minute radio adaptation of the movie on June 5, 1944 with Edward G. Robinson and Claire Trevor reprising their film roles.
Ralph Richardson played the role successfully in London, and subsequently Cedric Hardwicke did the same in New York.
In the five films Robinson and Bogart made together Robinson kills Bogart once, Bogart kills Robinson once, and they kill each other twice.
Edward G. Robinson, Humphrey Bogart And Claire Trevor starred together again in Key Largo (1948).