Ida Lupino and Howard Duff head a cast in a story about a Women's Prison. But these two who were married in real life at the time are hardly romantic leads in this film.
Ida plays the head of a female division of a state prison, the overall warden is Barry Kelley. The message the film is trying to give although the reason for it is pretty exotic is that boys will be boys and that women ought to be in a separate facility altogether. The main plot line of this film is convict Warren Stevens trying to get over to the women's division to see his wife Audrey Totter. Stevens's successful visits which get Totter pregnant get the whole thing crashing around Lupino's head.
It's all been done before, especially by some in this cast. Howard Duff was one of the convicts in Brute Force and there are definite elements of that film carrying over here. More so even than the classic Caged in which Jan Sterling also played the same kind of brassy dame who knows the ropes.
In Caged you'll remember the chief villain was the sadistic guard Harper played by Hope Emerson, the warden was the sympathetic Agnes Moorehead. Here the corruption stinks at the top where Lupino takes out her own unfulfilled life on the inmates. The entire cast performs remarkably well, especially Lupino and Sterling.
As for how it ends, if you've seen another Ida Lupino classic, They Drive By Night than you kind of know what happens to her. Still Women's Prison is worth seeing it again.