Greene's career began as a nightclub singer in clubs such as The Brothers and Sisters, Continental Baths, Grand Finale, and Reno Sweeney's. She received rave reviews from critics such as Rex Reed, George Bell, and John S. Wilson. Around this time, she befriended the late Peter Allen. Her first starring role on Broadway was as the lead in the unsuccessful Broadway show Rachael Lily Rosenbloom (And Don't You Ever Forget It), which had 7 previews in 1973 but closed before officially opening. She then played the starring role of Chrissy in Joseph Papp's production of In the Boom Boom Room at the Off-Broadway Public Theatre in November to December 1974. Her reviews brought her to the attention of Paul Mazursky, who was at that time casting Next Stop, Greenwich Village (1976). She was cast in the role of Sarah, her first starring role in a film.