Although educated as a painter and decorator, Sergio Tarquinio turned to making comics in 1945. His first exploit was 'Luna d'Argento' with Editions DEA, followed by Roy d'Ami's 'Blek e Gionni'. He emigrated to Argentina in 1948, where he joined the "Group of Venice", which consisted of artists like Hugo Pratt, Ivo Pavone, Mario Faustinelli and Dino Battaglia, who were all working for Editorial Abril. Tarquinio drew covers for Misterix and created the seriesk 'Alan Blood', El Inspector Slop' and 'El Secreto de la Piramide'.
Back in Italy in 1952, Tarquinio started a collaboration with the publisher Dardo, for whom he realized series such as 'Marussia', 'Ray Fox' and 'Condor Gek'. He also contributed to Classici Illustrati and Ardito. Through the studios of Roy d'Ami, he contributed to several publications of the British Fleetway group, including the Thriller Picture Library ('Dick Daring'), Sun Comic ('Crazy Horse') and the Cowboy Picture Library ('Kansas Kid', 'Kit Carson', 'Davy Crockett', etc.).
In 1959, he started working for Sergio Bonelli, illustrating 'Giubba Rossa' and 'Giudicci Bean'. Starting in 1965, he was active in the superhero genre, illustrating comics with 'Batman' and 'Superman' for Mondadori. he also drew 'Red Buck' for Nuova Collana Araldo, and contributed to Gino d'Antonio's 'La Storia del West'. In the 1980s, Tarquinio worked mainly for Bonelli publishers, as well as drawing the 'Ken Parker' series.