The residents of the apartment building on Rue Montmartre are a motley crew of oddballs and eccentrics. The daring son of a professor couple is in love with a sexy student who supplements her pocket money by working as an au pair. And then there's Monsieur Calomel, the crazy but helpful neighbor who's always ready with a funny face...
Robert Lamoureux
as Robert Langlois, law student
Fernand Ledoux
as Fernand Langlois, father, professor
Gaby Morlay
as Gabrielle Langlois, mother
Nicole Courcel
as Catherine Liseray, young neighbor
Louis de Funès
as Mr. Calomel, neighbor on the floor above
Gaston Modot
as Street violinist
Madeleine Barbulée
as Marie-Louise, first maid
Yolande Laffon
as Madeleine Sautaupain, Mom's friend
Robert Rollis
as Léon “Alibi”, friend of Robert
Sophie Sel
as Student of Mr. Langlois
Dominique Davray
as Neighborhood butcher
Françoise Hornez
as Nicole
