Minnelli, 67, took the stage alongside her 60-year-old sister Lorna Luft at a benefit for The Actors Fund's Phyllis Newman Women's Health Initiative and Tower Cancer Research Foundation's Dr. Philomena McAndrew Fund at Birdland, Minnelli's website said.
"This event means the world to me," said Luft, a breast cancer survivor. "I'm so grateful to be feeling so well and performing again."
"Nothing was going to stop me from coming here tonight," Minnelli said backstage before the show. "Lorna asked me to be here and I wouldn't let her down."
Minnelli returned to the hospital after the show for further treatment on her wrist, which was broken in three places, her website said.