During World War II, he started to work as an illustrator for satire magazines, together with Federico Fellini and Ettore Scola, and he met Agenore Incrocci, better known as "Age".
These include some of the most famous of all, such as Sergio Leone's The Good, the Bad and the Ugly and Mario Monicelli's Big Deal on Madonna Street.
After closing his relationship with Age, he wrote several movies with Ettore Scola, and the first works of directors such as Francesca Archibugi and Paolo Virzì.
His third Nomination to Oscar was for Il Postino: The Postman, written with his son Giacomo.
The film Tormenti (2011), adapted from his graphic novel, was released shortly after his death.