Almost entirely improvised by its mostly non-professional acting ensemble.
The only scripted scenes were those between Sal and Larry Burrows. The character of Larry Burrows is a reference to Mr. Destiny. Richie Devaney played 'Young Larry Burrows' in Mr. Destiny and reprised the role for Muggers: The Movie.
While filming, Ned Martin, Mark Breese, Greg Deliso, Kevduce, and Henry Torbin were asked to leave Lincoln Center. The same crew was threatened by a street vendor outside of the Central Park carousel after a miscommunication.
Kevduce, gained 30 pounds to play the role of Warrington Bartleby. His moustaches, although quite authentic looking, were artificial. His hat once belonged to Tom Easton, the grandfather of Greg Deliso, for whom Greg's character was named.