* Paul Muni as Louis Pasteur
* Josephine Hutchinson as Marie Pasteur
* Anita Louise as Mme. Meissonier
* Donald Woods as Dr. Roux
* Henry Stephenson as Dr. Charbonnet
* Fritz Leiber as Dr. Lister
* Frederick Burton as Napoleon III
* Holmes Herbert as Dr. Vallery-Radot
* Arthur Hohl as Dr. Chamberland
* Edward Brophy as Michel
* Robert Greig as The Abbot
* Halliwell Hobbes as The Bishop
* Alexander Kirkland as Dr. Grancher
This film was a biographical drama about the famous French chemist and microbiologist Louis Pasteur. It was nominated for the Academy Award for Best Picture, and Paul Muni won the Best Actor Oscar for his portrayal of Pasteur.