Born Concetto Francesco Diogene in Catania, he was the son of a Sicilian father and a Ligurian mother.

[1][2] In Genoa he completed his studies, and also started acting in a little theater of a parish.

[1][2] Since the early 1970s, he was one of the most active character actors in Italian cinema, often cast in humorous roles.

[1][2] He was also cast in several international productions, such as Midnight Express (in the role of Yesil, the Turkish lawyer who unsuccessfully defended Billy Hayes in court) and The Name of the Rose, mainly thanks to his foreign language skills.

[1][2] Diogene was also active as a stand-up comedian, and he was the organizer of the beauty contest "Miss Top Model Universe".