After I Am a Fugitive from a Chain Gang (1932) led to prison reform in six states, Warners producer Jerry Wald wanted to do the same for women's prisons and sent former newspaper reporter Virginia Kellogg out. She had written a novel that became a Kay Francis film, Mary Stevens, M.D. (1933), about a doctor who bears a child out of wedlock. She had also written well-researched original stories that were the basis for T-Men (1947), about treasury agents, and White Heat (1949), starring James Cagney as a psychotic gangster. She spent months doing research for Caged (1950) at prisons around the country, and was even briefly incarcerated in one of them. Her research is evident in the script with authentic prison slang of the era, and details of prison life, such as the caste system, and the tedium of daily life. Virginia Kellogg and Bernard C. Schoenfeld received an Oscar® nomination for Caged (1950)'s story and screenplay.
When offered a role in this film, Bette Davis turned it down, telling Warners she wasn't interested in making "a dyke movie".
For its time, this film was a shockingly realistic depiction of women's prisons, persuasively making the argument that the unfeeling manner in which incarcerated women were treated by America's penal system contributed to the perpetual problem of recidivism.
Jon Walmsley, Ellen Corby's co-star from The Waltons (1972), recalls her telling him that to make her role stand out in this film, she decided her character would be the convict who was happy to be in prison.
In an early example of product placement, Snickers, Mason Mints, and Life-Savers are clearly visible when Harper opens the drawer in her room. Juicy Fruit gum and a 5th Avenue candy bar also can be seen.