Born in Cuceglio, in the province of Turin (Piedmont), Zanotto moved with his family at age thirteen to Argentina.

[1] In 1953 he started to work at Editorial Codex where he worked on stories by other authors, and in subsequent years did adventure comics, westerns and drew early stories for Tatin and The Phantom.

In 1955, with writings by Alfredo Grassi, he created Ric de la Frontera, and that same year began working on El Mundo del hombre rojo (Indian legends of North America).

With Ray Collins (Eugenio Zappietro) he created the fanta-prehistoric Henga (Yor in Italian) using his and Diego Navarro's scripts (the 1983 film Yor, the Hunter from the Future was based on this graphic novel), the western Wakantanka with scripts by Héctor Germán Oesterheld, and the science fiction Bárbara (1979–1983) and Nueva York año cero (in 1984 for la EPC of Rome), both written by Ricardo Barreiro, Cronicas del Tiempo Medio ("Chronicles of the Middle Time") written by Emilio Balcarce and Penitenciario with scripts by Barreiro.

Falka, the continuation of Horizontes Perdidos of 1993, was Zanotto's first work also as a writer, and lasted until 2003.