[citation needed] After leaving his footballer career for an injury, Di Marzio debuted as a manager in 1968 in Serie C.[1] He had his breakout as the coach of Catanzaro, where after his second season in charge, led the team to an unexpected promotion to Serie A in 1976.

Di Marzio had shown enough to earn a move to Napoli for the following season.

[2] With Napoli, Di Marzio was a Coppa Italia finalist in 1978, losing the trophy against Inter Milan.

[3] Di Marzio successively took on a career as a football pundit and manager, working as Maurizio Zamparini's collaborator during his periods at Venezia and Palermo, as well as transfer consultant and scout at Queens Park Rangers.

[3] Di Marzio's son, Gianluca, is a renowned Italian football journalist and pundit, working with Sky Italia.