From 1994 through 1998, Marzilli played the role of Vince Carter in the family science fiction television series The Secret World of Alex Mack, for which he is probably best recognized. He had previous guest-starred in an episode of Cheers (starring Kelsey Grammer) and several episodes of Tales from the Darkside, including one with Carolyn Seymour and Lawrence Tierney. More recent TV appearances include Seven Days (with Jeff Kober and Norman Lloyd) and The Practice (starring Bill Smitrovich).