Mustillo was born in Buffalo, New York. He has guest starred in over 50 episodes of television and appeared in over 20 films. He was a series regular on a good but short lived show called Man of the People (1991), starring James Garner. He appeared for two seasons on Dreamworks' first hour-long drama, High Incident (1996), executive produced by Steven Spielberg. He had a recurring role on The Sopranos (1999) as Tony Soprano's gardener, Sal Vitro. He appeared in The Narrows (2008) and was recently seen on the ESPN mini-series The Bronx Is Burning (2007) as famous real-life sports writer Maury Allen. Mustillo wrote and starred in "Bartenders", a one man stage show that ran for a year at the John Houseman Theatre in New York City. His hobbies include visiting museums and exploring all New York has to offer.