[3] Guastaferro then attended at The Theatre School at DePaul University, where he earned the Master of Fine Arts degree.
[3] He began his career in 1979, first appearing on the stage production of Sexual Perversity in Chicago, where he served as the replacement of actor, comedian and musician Jim Belushi.
!, Hardcastle and McCormick, CSI: NY, Melrose Place, Hunter, The West Wing and Brooklyn South.
He played the recurring role of John Kousakis in the crime drama television series Wiseguy.
Guastaferro appeared in films such as Things Change, Eyes of an Angel, Touch Me, Nothing in Common, State and Main, and Trouble Bound.