Born in Naples, Italy, the son of a lawyer and a seamstress, Marotta suffered from bone tuberculosis in his childhood and adolescence.

[1] Starting from the early 1920s he collaborated with newspapers and magazines with short stories and poetries; in 1924 he moved to Milan, where he was employed first at Mondadori as a proofreader and archivist and later at Rizzoli as editor.

[1][2] He then collaborated with the satirical magazines Bertoldo and Guerin Meschino and with the newspapers La Stampa and Corriere della Sera.

[1] Marotta had his breakout in 1947, with the novel L'oro di Napoli, which won the Paraggi Prize, was a massive bestseller, and was later adapted in the Vittorio De Sica's film The Gold of Naples.

[1] He authored several comedy plays, notably Il califfo Esposito (1956) and Bello di papà (1957), both starring Nino Taranto.