Mastrogiorgio has appeared in television shows such as The Sopranos and Law & Order (in addition to two of the show's spinoffs, Law & Order: Special Victims Unit and Law & Order: Criminal Intent). Earlier in his career, he appeared in the TV mini-series based on the Mario Puzo novel, The Last Don and also The Last Don II.
In addition to Liberty City Stories, Mastrogiorgio has provided his voice for many other projects. These include the video games Batman: Dark Tomorrow and The Sopranos: Road to Respect and also the movies Brother Bear and Underdog.
He has also appeared on stage in plays such as The Two Gentlemen of Verona at the New York Shakespeare Festival and The Taming of the Shrew at both the Denver Center for the Performing Arts and the Old Globe Theatre in San Diego.