The identity of the actress Celeste Holm who did the voice-over for Addie Ross was kept secret when the film was released. The studio held a number of "Who is Addie?" contests around the country where moviegoers could guess the actress' name.
Joseph L. Mankiewicz had a real battle with the American censors at the time who would not permit him to use words like "laxative" and "toilet" in his script. He got his revenge with a famous double-entendre laden exchange which used words like "penetration" and "saturation".
At one point the film was called "A Letter to Four Wives". Upon submitting the adapted screenplay to 20th Century-Fox chief Darryl F. Zanuck, Joseph L. Mankiewicz mentioned that he found it too long and asked how he felt the movie could be shortened. "Take out one of the wives," Zanuck replied. Originally, the movie would have featured Anne Baxter as the fourth wife. Zanuck didn't feel Baxter's segment was as strong as the other three, so that one was cut.
Celeste Holm was initially not remotely interested in providing the off-screen voice of the letter-writer and was more inclined to take the part that eventually went to Ann Sothern. Joseph L. Mankiewicz persuaded her that her involvement would be absolutely crucial to the film's success.
Linda Darnell and Joseph L. Mankiewicz became romantically involved during the making of the film. Darnell considered Mankiewicz to be the great love of her life but he refused to leave his wife. He later remarked that she was "a marvelous girl with terrifying personal problems".
Linda Darnell's home which shakes when the train passes by was inspired by Joseph L. Mankiewicz's childhood home in New York City. His father would always stop talking as he waited for the Third Avenue El to pass by.