Joan Henry's original novel 'Who Lie In Gaol' was based on her own experiences of prison. In debt from gambling, she took a forged cheque from a friend as a loan, and was convicted at the Old Bailey in 1951. Sentenced to twelve months, she served eight, primarily in Holloway Prison of which she was very critical, and later at Askham Grange Open Prison. The Glynis Johns character is based on her, although Henry thought her "a bit goody-goody".
Two years later, J. Lee Thompson again directed Diana Dors in Yield to the Night (1956), also based on a novel by Joan Henry.
Prolific character actress Marianne Stone appears unbilled as a fellow prisoner who comforts Diana Dors' character.
The open prison depicted in this film, "The Grange", is based on HM Prison Askham Grange, in Askham Richard, North Yorkshire. It was established in 1947 and was the first open women's prison in the country. As of 2020 it continues to operate as such.