George Raft passes a young hood who is flipping a coin in his hand and he asked him where he learned a "cheap trick" like that. That trick was one of Raft's gimmicks in many of his earlier gangster movies.
Jerry Lewis was offered the role of Jerry/Daphne but declined because he didn't want to dress in drag. When Jack Lemmon received an Oscar nomination for the role that Lewis gave up, Lewis claims he sent him chocolates every year to thank him and now regrets not taking the part.
Marilyn Monroe recorded a vocal version for the theme to the film. It was to be played over the opening credits, but an instrumental overture took its place in the final version. The title track later appeared on an LP in the mid-'70s, with Marilyn's three other songs from the film.
Marilyn Monroe required 47 takes to get "It's me, Sugar" correct, instead saying either "Sugar, it's me" or "It's Sugar, me". After take 30, Billy Wilder had the line written on a blackboard. Another scene required Monroe to rummage through some drawers and say "Where's the bourbon?" After 40 takes of her saying "Where's the whiskey?", 'Where's the bottle?", or "Where's the bonbon?", Wilder pasted the correct line in one of the drawers. After Monroe became confused about which drawer contained the line, Wilder had it pasted in every drawer. Fifty-nine takes were required for this scene and when she finally does say it, she has her back to the camera, leading some to wonder if Wilder finally gave up and had it dubbed.
Marilyn Monroe wanted the film to be shot in color (her contract stipulated that all her films were to be in color), but Billy Wilder convinced her to let it be shot in black and white when costume tests revealed that the makeup that Tony Curtis and Jack Lemmon wore gave their faces a green tinge.
Marilyn Monroe was pregnant during the filming, as a result she looked considerably heavier. She had no known children and several miscarriages in her life. Due to her pregnancy, most of the publicity still photos were posed for by both Sandra Warner (who had an uncredited role as one of the band members) and Monroe's frequent stand-in Evelyn Moriarty with Monroe's head superimposed later.
Jack Lemmon wrote that the first sneak preview had a bad reaction with many audience walkouts. Many studio personnel and agents offered advice to Billy Wilder on what scenes to reshoot, add and cut. Lemmon asked Wilder what he was going to do. Wilder responded: "Why, nothing. This is a very funny movie and I believe in it just as it is. Maybe this is the wrong neighborhood in which to have shown it. At any rate, I don't panic over one preview. It's a hell of a movie." Wilder held the next preview in the Westwood section of Los Angeles, and the audience stood up and cheered.
Billy Wilder referring to Marilyn Monroe while making the movie: "We were in mid-flight, and there was a nut on the plane." Indeed, Wilder publicly blasted Monroe for her behavior, and she was not invited to the wrap party.
Tony Curtis has said that he asked Billy Wilder if he could imitate Cary Grant for his stint as the millionaire in the movie. Wilder liked it and they shot it that way. Apparently, Grant saw the parody of himself and stated, "I don't talk like that."
Tony Curtis's voice as Josephine was dubbed by Paul Frees (according to co-writer I.A.L. Diamond). Curtis confirmed it by stating the voice you hear as Josephine is a combination of his voice and Frees'. Curtis says he had trouble maintaining a high-pitched voice for an entire take.
Porgy and Bess was being filmed right next to where the indoor scenes for this film were being shot. Sammy Davis Jr., Sidney Poitier and Dorothy Dandridge frequently visited the set.
Georg Thomalla, who starred in the German original, Fanfaren der Liebe, dubbed Jack Lemmon in the German version of this movie.
A cabaret dancer (a man who played women on stage) tried to teach Tony Curtis and Jack Lemmon to walk in heels. After about a week, Lemmon declined his help, saying he didn't want to walk like a woman, but a man trying to walk like a woman.
A preview audience laughed so hard in the scene where Jack Lemmon announces his engagement that a lot of the dialogue was missed. It had to be re-shot with pauses (and the maraca gimmick) added.
According to George Raft, Marilyn Monroe suggested to Billy Wilder that he end the movie with Sugar and Spats tangoing off into the sunset. Wilder liked the idea, but decided on the ending with Osgood and Jerry.
According to Jules Faith in "The Bronfmans", the only person who ever dared mock Lew Wasserman's "Music Corporation of America" was Billy Wilder in this movie. The musicians played by Tony Curtis and Jack Lemmon, looking for work, charge into an office labeled "Music Corporation of America". The only occupants are two frowzy women drinking gin.
Director Billy Wilder had originally planned to cast Mitzi Gaynor in the role of "Sugar Kane Kowalczyk", but when Marilyn Monroe became available, he used her instead.