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)

Pierre Monda

Little boy (uncredited)

Charles Vissières

Frémy, old doctor (uncredited)