Pasteur

Sacha Guitry Louis Pasteur

Maurice Schutz Grandfather

José Squinquel Émile Roux

Jean Périer Doctor

André Marnay Doctor

Pierre Labry Doctor

Armand Lurville The first witness

Camille Cousin The second witness

Henry Bonvallet Sadi Carnot, President of the Republic

Gaston Dubosc President of the Academy of Medicine

François Rodon Little Joseph Meister

Louis Maurel Jules Guérin

Louis Gauthier Poggiale

Pierre Athon Student

Pierre Huchet Servant (uncredited)

Camille Beuve Joseph Lister (uncredited)

Julien Bertheau Student (uncredited)

Gaston Allain Student (uncredited)

Félix Clément Student (uncredited)

Jean Francey Student (uncredited)