Totò as lo smemorato

Nino Taranto as prof. Ademaro Gioberti

Erminio Macario as Nicola Politi

Aroldo Tieri as dott. Alessandro Zannini

Andrea Checchi as avvocato Rossetti

Franco Volpi as pubblico ministero

Mario Pisu as avvocato Dell'Orso

Elvi Lissiak as Wife of Polacic

Riccardo Billi as Fernando Meniconi

Enrico Viarisio as Il Ministro

Franco Giacobini as Giornalista

Gisella Sofio as Giornalista Milanese

Pietro Carloni as Francesco Ballarini

Mario Castellani as Giorgio Ballarini

Gianni Rizzo as Ragionere

Franco Ressel as Agente Pubblicitario

Yvonne Sanson as Linda Ballarini

Antonio Acqua as Presidente del Tribunale (uncredited)

Anna Lina Alberti as Moglie dello Smemorato (uncredited)

Angelo Casadei as Carabiniere (uncredited)

Sergio Corbucci as Man waiting for Minister (uncredited)

Consalvo Dell'Arti as Natale (uncredited)

Mimmo Poli as L'Uomo panchina (uncredited)