In this true story an Australian nurse develops a treatment for infantile paralysis that often prevents crippling; but doctors refuse to let her treat their patients because they do not understand her new theory about polio.
In Queensland, Australia, Elizabeth Kenny (Rosalind Russell) comes home after graduating and tells Dr. Aeneas McDonnell (Alexander Knox) that she plans to be a bush nurse. Rural people thank her and give her a horse. Kenny learns that a girl has infantile paralysis, but no treatment is known. She observes her legs and tries heat. Kenny's parents welcome Kevin Connors (Dean Jagger), and he goes with Kenny to see the girl who is now paralyzed. Kenny gets her to move her leg. Kenny tells Kevin that she will marry him. She tells McDonnell that she had six cases, and all have recovered. He shows her children who are getting worse. McDonnell and Kenny tell Dr. Brack (Philip Merivale) how she treated them with heat and by re-educating the muscles that were alienated. Brack denies that her patients had polio. McDonnell asks Brack to let Kenny try her treatment on some of his cases, but he refuses. McDonnell advises her to take the worst cases and heal them.
Kenny treats children in her clinic. Doctors take her patients away after she has helped them; but they are still in denial. Kevin goes off to war, and Kenny tells McDonnell that she is going to serve in France too. She kisses wounded Kevin, whom she got transferred. McDonnell tries to use Kenny's methods as Brack watches. McDonnell gives up, and Kenny returns. Learning of a polio epidemic, she opens a clinic. Kevin comes back and says he'll wait, but she won't give up her work. A woman brings in a girl, and Kenny takes off her braces. Kevin leaves.
McDonnell tries to stop Kenny from going to Brisbane, where Brack is. Kenny's patients are taken away. She interrupts Brack's lecture and asks why he prevents her from doing her work. Brack lets Kenny explain her theory. They debate, and he dismisses her. Two doctors are interested in her treatment, and McDonnell brings a letter saying that she is wanted in London. People support her.
At the London airport Kevin sees Kenny in 1938. The government has asked her to return to Australia because of an epidemic. A doctor tells McDonnell that a commission condemned her work. McDonnell tells her that they want to close the Kenny clinics. She is going to America, and McDonnell checks her heart. He says that people are more important than the system.
In San Francisco reporters question Kenny. Two years later Kenny is leaving, but a reporter tells her that she is wanted and needed in Minneapolis. Three years later Kenny dictates a letter to McDonnell of her success, but she gets a telegram he died. Kenny re-educates doctors. The national report is negative about Kenny, but she responds strongly and teaches. In the final scene children sing "Happy Birthday" to her.
This biography depicts the arrogance and prejudices
of doctors that may prevent new methods of healing because they
do not fit into their old theories. Despite being held back because
she was only a nurse, Kenny helped thousands of children avoid
much pain and have much better lives.