In 1980, while continuing his career in pharmaceutical distribution, Nasso accepted a position as a personal assistant to director Sergio Leone. Under Leone, Nasso worked on the New York portion of "Once Upon a Time in America" (1984), and participated in the development of two films: "In God's Name" and "Saint Peter's Banker". At this time, Nasso began to attend courses and seminars in film production at Cinecittà Studios in Rome, Italy. From 1981 to 1983, while still developing projects with Leone, Nasso went on to produce a television pilot for a Fox TV show entitled "Behind the 8 Ball,” starring Jerry Orbach, John Amos, and Jimmy Baio.