Born in Rome, Guastaveglia made his professional debut in 1908, in the magazine Il Travaso delle idee, and collaborated with other publications including Vamba's Corriere della Domenica.
[1] He then started collaborating, under pseudonyms, with other publications, including Corriere dei Piccoli and Il Giornalino della Domenica.
[1][3] In 1931, Guastaveglia began collaborating with Il Popolo di Roma, a newspaper founded in 1925 to replace the Roman edition of Il Popolo d'Italia, and which under the direction of Paolo De Cristofaro employed many anti-fascist intellectuals, including Adriano Tilgher, Mario Missiroli, Corrado Alvaro and Mario Vinciguerra [it].
[1] In 1944, he founded the "Funny Faces Shop" with his Marc'Aurelio colleagues Federico Fellini and Carlo Ludovico Bompiani.
[1] He was also active as a caricaturist, a painter, a children book author and an essayist, notably writing an encyclopaedia of humour ("Enciclopedia dell'Umorismo") in four volumes.