Working titles of the film include Fanny, Madelon, Life on the Waterfront and Man of the Waterfront. The film only credits the play Fanny by Marcel Pagnol as the original source material, however, some incidents within the film are based on the French films Marius (1931), directed by Alexander Korda, Fanny (1932), directed by Marc Allegret, and Cesar (1936), which Pagnol directed. All of those films were written by Pagnol and based on his own plays. According to news items and early production charts for the film, Ernest Vajda was to be the screenwriter; however, reviews and SAB only credit Sturges with the screenplay, and SAB specifically notes that Vajda was not to receive credit as a contributing writer on the picture.
       The file on the film in the MPPDA/PCA Collection at the AMPAS Library includes portions of a screenplay written by Sturges in late 1933 or early 1934, when the story was being considered for production at Universal. Jul 1934 correspondence in the file mentions that the film was to be supervised by Henry Henigson at Universal, with William Wyler set to direct from Sturges' screenplay. The submitted script was rejected by Joseph I. Breen, Director of the PCA. Universal apparently decided to drop the project, and a letter sent from PCA president Will H. Hays to Paramount head Adolph Zukor implied that a film utilizing Sturges' script was later considered by Paramount. The letter also stated that it was Hays's understanding that the title of Pagnol's original play would not be used for the released film. Information in the file, beginning on 20 Jul 1936, indicates that M-G-M had bought the property and was also planning to make the picture based on Sturges' script. According to a letter from Breen to M-G-M producer John W. Considine, Jr., M-G-M's submission was essentially the same as the Sturges script earlier accepted by his office. It has not been determined at what point Sturges' script for Universal was accepted. Though subsequent letters from Breen advised "caution" in presentation, its basic story was "acceptable." Few changes were suggested beyond Jul, 1936, although M-G-M was advised not to allow the baby's genitals to be exposed in the bath scene, and when the baby's temperature is taken to "be certain that there is no possibility of an inference that they are taking a rectal temperature of the child." Although the picture was approved on 15 Mar 1938 by Breen, subsequent to the film's release, Rev. John J. McClafferty, Executive Secretary of the National Legion of Decency wrote to Breen expressing his outrage at the picture and its "lowering the standards" which the code was supposed to uphold. McClafferty also said that the Legion of Decency had perceived a lessening of diligence on the part of the PCA. A Var news item on 28 May 1938 speculated that the reason why the film's release was delayed for almost six months after the end of production was that the subject matter of the film was considered "dangerous" in light of the Neely Bill that was up before Congress, part of which had implications for censorship of films.
       According to news items, Luise Rainer was originally scheduled to play Madelon, however, a bad cold prevented her from appearing and her role went to Maureen O'Sullivan. News items also noted that this was Henry Henigson's first production for M-G-M. In addition to the three French films mentioned above, Pagnol's trilogy was also the source for an Italian film called Fanny made in 1933, a 1934 German film entitled Der Schwarze Walfisch, a 1954 Broadway musical entitled Fanny written by Joshua Logan and S. N. Behrman, with music and lyrics by Harold Rome and a 1961 Warner Bros. film of the same name directed by Logan with Leslie Caron, Maurice Chevalier and Charles Boyer. That film was also based in part on the Broadway play, but was not a musical (see AFI Catalog of Feature Films, 1961-70; F6.1460). Though neither the 1938 film nor Preston Sturges received any onscreen credit for the 1961 Fanny, many situations and portions of the dialogue of the earlier film were contained in the latter.