Trivia

For the "Make 'em Laugh" number, Donald O'Connor revived a trick he had done as a young dancer: running up a wall and completing a somersault. The number was so physically taxing that O'Connor ended up in a hospital bed for a week after its completion. He suffered from exhaustion and carpet burns. After an accident ruined all of the initial footage, O'Connor agreed to do the difficult number all over again.

Donald O'Connor smoked four packs of cigarettes a day during production. "Getting up those walls was murder," O'Connor stated in an interview. "They had to bank one wall so I could make it up and then through another wall. We filmed that whole sequence in one day. We did it on a concrete floor. My body just had to absorb this tremendous shock. Things were building to such a crescendo that I thought I'd have to commit suicide for the ending. I came back on the set three days later. All the grips applauded." However, no one had checked the camera's aperture, and the footage was unusable. "So the next day, I did it again!" O'Connor recalled. "By the end, my feet and ankles were a mass of bruises."

Gene Kelly was a severe taskmaster with 19-year-old Debbie Reynolds, who had never danced to this degree before rehearsals started. "He came to rehearsals and criticized everything I did and never gave me a word of encouragement," Reynolds recalled. Fred Astaire, who was in an adjacent studio, found her sobbing under a piano and reassured her that all of her hard work was worth the effort. Relations between Kelly and Reynolds further deteriorated during their on-screen kiss when Kelly forcibly stuck his tongue in Reynolds' mouth without her consent. "I was an innocent kid... It felt like an assault," Reynolds wrote in her memoir. "I was stunned that this 39-year-old man would do this to me."

In interviews, Debbie Reynolds stated that she "learned a lot from Gene Kelly. He is a perfectionist and a disciplinarian... Every so often he would yell at me and make me cry. But it took a lot of patience for him to work with someone who had never danced before. It's amazing that I could keep up with him and Donald O'Connor." Kelly commented on her work, "Fortunately, Debbie was strong as an ox... also she was a great copyist, and she could pick up the most complicated routine without too much difficulty... at the university of hard work and pain." After this film, Reynolds and Kelly never worked together again.

A microphone was hidden in Debbie Reynolds' blouse so her lines could be heard more clearly. During one of the dance numbers, her heartbeat can be heard, mirroring what happens to Lina Lamont in the movie itself.