Donald O'Connor had separated from his wife of ten years. She and Dan Dailey, who played O'Connor's father, were dating during the shooting of the film. After filming wrapped, the O'Connors divorced and shortly thereafter Gwen Carter and Dan Dailey married.
One day, Marilyn Monroe's husband, Joe DiMaggio, visited the set. He refused to be photographed with Monroe, but insisted on being photographed with Ethel Merman, whom he called "my favorite star."
Marilyn Monroe was promised the lead role in The Seven Year Itch (1955) if she appeared in this film to boost its box-office potential. The role of Vicky was written especially for this purpose, and songs such as "Heat Wave," originally intended for Ethel Merman, were reassigned to her.
Top-billed Ethel Merman was concerned that audiences might focus on Marilyn Monroe's stunning figure rather than Merman's vocals in the film's finale. She specifically requested that costume designer Travilla design a gown that would allow Ethel to compete with Marilyn. The result was a white satin dress with "wings" atop its bodice, that gave the illusion that Merman was at least as "busty" as Monroe.
As Vicky passes Tim in the beginning of the movie, he says to her, "Well, if it isn't Ethel Barrymore!" Gene Kelly said the same thing to Debbie Reynolds in Singin' in the Rain (1952), in which Donald O'Connor also starred.