Billy Wilder wrote the script for the film Some Like it Hot. The plot is based on a screenplay by Robert Thoeren and Michael Logan from the 1936 French film Fanfare of Love. However, the original script for Fanfare of Love was untraceable, so Walter Mirisch found a copy of the German remake Fanfaren der Liebe. He bought the rights to the script and Wilder worked with this to produce a new story. Although Some Like It Hot has been seen as a remake of Fanfare of Love, as both films follow the story of two musicians in search of work, Wilder was the creator of the gangster subplot that kept the musicians on the run.
The studio hired Barbette, a famous female impersonator, to coach Lemmon and Curtis on gender illusion for the film.
Marilyn Monroe worked for 10% of the gross in excess of $4 million, Tony Curtis for 5% of the gross over $2 million and Billy Wilder 17.5% of the first million after break-even and 20% thereafter.
Tony Curtis was spotted by Billy Wilder while he was making the film Houdini (1953), as he thought Tony would be perfect for the role of Joe. "I was sure Tony was right for it," explained Wilder, "because he was quite handsome, and when he tells Marilyn that he is one of the Shell Oil family, she has to be able to believe it". Wilder's first idea for the role of Jerry was Frank Sinatra, but he never came to the audition. Jerry Lewis and Danny Kaye were also considered for the role of Jerry. Finally, Wilder saw Jack Lemmon in the comedy Operation Mad Ball and selected him for the role of Jerry. Billy Wilder and Jack Lemmon made numerous films together until 1981, among them The Apartment and several films with Walter Matthau.
According to York Film Notes, Billy Wilder and I.A.L. Diamond didn't expect such a big star as Marilyn Monroe to take the part of Sugar in fact, Wilder said, "Mitzi Gaynor was who we had in mind. The word came that Marilyn wanted the part and then we had to have Marilyn." Wilder and Monroe had already made the film The Seven Year Itch together in 1955.
The film was made in California during the summer and autumn of 1958. Many scenes were shot at the Hotel del Coronado in San Diego which appeared as the "Seminole Ritz Hotel" in Miami in the film. The Hotel in San Diego fitted into the era of the 1920s and was near Hollywood, so Wilder chose it although it was not in Florida.
There were many problems with Marilyn Monroe, who lacked concentration and suffered from addiction to pills. She could not memorize many of her lines and required 47 takes to get "It's me, Sugar" correct, instead saying either "Sugar, it's me" or "It's Sugar, me". Tony Curtis and Jack Lemmon made bets during the filming how many takes Marilyn would need to get it right. For the scene with Shell Jr. and Sugar at the beach three days for shooting were scheduled. Although Marilyn had plenty of complicated lines, the whole scene between Shell Jr. and Sugar was completely finished in only 20 minutes. Monroe's acting coach Paula Strasberg and Monroe's husband Arthur Miller both tried to influence the production, which Wilder and other crew members found annoying.
Billy Wilder said in 1959 about filming another movie with Marilyn Monroe: "I have discussed this with my doctor and my psychiatrist and they tell me I'm too old and too rich to go through this again." But Wilder also admitted: "My Aunt Minnie would always be punctual and never hold up production, but who would pay to see my Aunt Minnie?" He also stated that Monroe played her part wonderfully.
The film's iconic closing line, "Nobody's perfect"—now ranked 78th on The Hollywood Reporter list of Hollywood's 100 Favorite Movie Lines—was never supposed to be in the final cut. Diamond and Wilder put it in the script as a "placeholder" until they could come up with something better, but never did.
With regards to sound design, there is a 'strong musical element' in the film, with the soundtrack created by Adolph Deutsch. It has an authentic 1920s jazz feel using sharp, brassy strings to create tension in certain moments, for example whenever Spats' gangsters appear. In terms of cinematography and aesthetics, Billy Wilder chose to shoot the film in black and white as Jack Lemmon and Tony Curtis in full drag costume and make-up looked 'unacceptably grotesque' in early color tests.