After several jobs in the advertising field, Renato Frascoli began his career in illustration in 1954, when he became an editor for Corriere dei Piccoli. He remained with the magazine for many years, and assisted during its transformations to Corriere dei Ragazzi and Corrier Boy. Under the direction of Giancarlo Francesconi, he made several comics for the magazine, that were scripted by Alfredo Castelli, Tiziano Sclavi, Mino Milani and Andrea Mantelli. He illustrated several episodes of 'Pecos Bill' and 'Il Piccolo Sceriffo' for the publications of Fasani and Torelli. With scriptwriter Clelia Ferrario, he created 'Super Woman' in 1966.
He was also present in several Catholic periodicals, such as Il Giornalino ('Astronave in Avaria' with De Santis) and PM (stories with scripts by Roudolph and Renata Gelardini). For the publisher Vincenzo Baggioli, he produced historical works like 'Storia d'Italia', 'Storia della Terra' and 'Storia delle Esplorazioni'. He was additionally present in Corriere della Sera, Corriere d'Informazione, Domenica del Correre, Visto, Oggi, Look and Learn, Astra, Corriere Salute and L'Europeo. He has illustrated many books for the publishers Nigrizia and La Sorgente, as well as cover illustrations for magazines and books, and advertising strips. For the daily La Provincia in his native town Como, he has made 'Storia di Como' and 'Storia della Diocesi Comasca', stories about local history.