The Honourable Mario Agosti, incorruptible politician, has a twin brother, Filippo, hedonist and swindler, the true black sheep of the family. Posing as the illustrious brother, Filippo comes into contact with the world of politics and finance, and is not slow to profit from the powerful characters whom he gets to know. Mario will have to serve the paradoxical consequences.

Vittorio Gassman
as Mario Agasti / Filippo Agasti

Lisa Gastoni
as Alma - moglie di Mario

Adrienne La Russa
as Kitty

Giampiero Albertini
as Santarini

Ennio Balbo
as Suocero di Agasti

Umberto D'Orsi
as Roberto Franceschini 'Pampero'

Fiorenzo Fiorentini
as Bertieri

Marisa Fabbri
as Wife of Mattia

Ettore Mattia
as Minister Mattia

Lino Banfi
as Journalist (uncredited)