A simple soldier in the Second World War, Rosario Cavadunni, known as Zazà, was taken from the cafeteria, where he served as a waiter and was assigned to Badoglio. The marshal, however - these are the days of the Armistice - just in time to see him while fleeing from Rome. Shipped to Germany, Zazà first entered the service of a senior German officer and then, upon the arrival of the allies, an American commander. When the war is over he returns to Italy and works as a servant in the home of a film producer who entrusts him with painful results. Subsequently, Zazà serves the family of a Roman nobleman, and then, a couple of spouses from the "particular tendencies". Finally, it is the turn of an oilman, the engineer Perigatti - whose wife, a former prostitute, is an old acquaintance of Zazà. He, who secretly finances the parties, plays him a bad shot and Zazà ends up in jail, where, after trying in vain to prove his innocence, will be happy to ask, always as a waiter, in the service of fellow prisoners.