Jill Clayburgh found out her agent at the time was actually pushing someone else for the role. She found another agent, got the role and received her first Emmy nomination.
Sally Kirkland auditioned for Jill Clayburgh's role.
The pinball machine that Wanda leans on in the arcade is a "Swinger" machine made by Williams Electronics from December 1972.
According to Gail Sheehy, Jill Clayburgh walked 42nd Street for days, practicing her skills, and even arranged to go on a van with working girls to understand their world better.
Near the beginning of the movie, a downtown New York City theater marquee indicates that The Taking of Pelham One Two Three (1974) is showing. Dick O'Neill, who plays Keogh in this movie, also appeared in "Pelham One Two Three." The marquee is even more significant for the fact that "Pelham One Two Three" was directed by Joseph Sargent, who was also this film's director.