When he was a kid he learned to play violin, showing a remarkable musical talent. Subsequently he graduated in piano and composing at S. Cecilia academy of music of Rome. In 1937 he was engaged in the orchestra of Rocco Grasso, who will have wanted as piano player in his band during next year. In 1939 he played with Sesto Carlini's orchestra, one of the most renowned Italian jazz bands of that time. After the war he's got back to alternate between jazz playing and light music playing and, at the same time, he has improved his music studies graduating at Conservatorio Santa Cecilia of Rome (1948).
In 1949 he was picked out to represent Italy at Festival du Jazz de Paris, where he played with Gorni Kramer at double bass and Gilberto Cuppini at drums. On the year after he started a long set of recordings (published with the title "Musica per i vostri sogni"). With same title, and another time with the title Eclipse, he carried out, in collaboration with Piero Morgan (Piero Piccioni), a series of radio shows, one of the first Italian experiments to present jazz piano performances with a string orchestra.
At the same time Trovajoli has made his debut, with Vatro pen name, as songs author (Č l'alba, Dimmi un po' Sinatra, ecc.).
In 1952, invited by Alberto Lattuada writing music for "Anna"'s soundtrack, he accomplished his first worldwide best seller "El Negro Zumbon". On the same year Trovajoli performed as a concert artist playing Gershwin musics under direction of A. Rodzinsky at San Carlo theatre in Naples and of Willy Ferrero at Basilica di Massenzio in Rome. In 1953, in addition to write music for the movie "Due notti con Cleopatra", he attended as orchestra director at Festival della canzone di Sanremo (he was present in 1957, too), where with his famous "Eclipse Orchestra", he joined Cinici Angelini, in the first edition when there was scheduled a double performance of songs. He gained another international success with the song "Che m'č mparato a ffŕ" brought out and recorded by Sophia Loren (1958). In 1962 Trovajoli, who had previously collaborated for some variety shows, composed for the musical comedy «Rugantino» by Garinei & Giovannini, written together with Pasquale Festa Campanile and Massimo Franciosa, catching experts' eye for the research made about Roman popular themes of the nineteenth century, ably echoed back in his compositions. He has gained the same results with "Ciao Rudy" and "Aggiungi un posto a tavola" always by Garinei & Giovannini. The most striking and catchy song from "Rugantino", "Roma, nun fa' la stupida stasera", became his third worldwide best seller. To remember in his soundtracks repertoire is the collaboration with directors as Vittorio De Sica, Marco Vicario, Dino Risi, Luigi Magni and Ettore Scola, whose he has created music in practice for all his filmography. In 2007 he carried off the "Premio Speciale David di Donatello" for his career.