Mattioli debuted in 1965 in the periodic comic book Il Vittorioso with Vermetto Sigh. He was also published in Corto Maltese and Frigidaire. Three years later he moved to London, where he made comics for the Mayfair magazine. In the early 70s, he created Pasquino for the Paese Sera newspaper. In 1973 he began his collaboration in the Il Giornalino, creating the character Pinky. In 1977, in association with Stefano Tamburini, he created the underground magazine Cannibale. In 1978, Cannibale published the first adventure of Joe Galaxy. In 1982, he created the Squeak the Mouse series. Mattioli was recognized with many prizes, including the French prize Phenix in 1971, the Yellow Kid(de) in 1975 and Romics d'Oro in 2009.