"Medication time!"

Louise Fletcher was so upset with the fact that the other cast members of "One Flew Over the Cuckoo's Nest" (1975) could laugh and be happy, while she had to be so cold and heartless, that near the end of production, she removed her dress and stood in only her panties to prove to the cast members she was not "a cold-hearted monster".

Fletcher was so disturbed by her own performance that she couldn't watch the film for years. In later interviews, she said that she found ways to make her character human, yet remain unsympathetic, ultimately deciding that Nurse Ratched actually did care about the patients, and felt she was doing what was best for them, but was ultimately misguided and drunk on her own power.

Director Milos Forman relied heavily on reaction shots to pull more characters into scenes. In some group therapy scenes, there were ten minutes of Jack Nicholson's reactions filmed, even if he had very little dialogue. The shot of Fletcher looking icily at Nicholson after he returns from shock therapy was actually her irritated reaction to a piece of direction from Forman.

Fletcher was signed a week before filming began, after auditioning repeatedly for over six months. Forman had told her each time that she just wasn't approaching the part correctly, but kept calling her back. She only realized that the part of Nurse Ratched was a hotly contested role among all the leading actresses of the day when a reporter visiting the set happened to casually mention it.

Anne Bancroft, Ellen Burstyn, Faye Dunaway, Colleen Dewhurst, Jane Fonda, Audrey Hepburn, Angela Lansbury, Jeanne Moreau, Shirley MacLaine, and Geraldine Page were all considered for the role.