Winehouse, 24, reportedly has long battled an addiction to drugs. She was hospitalized this month after she collapsed in her home, and reportedly began undergoing treatment for the early stages of the lung ailment emphysema.
Her recent health crisis caused some to doubt she would be able to perform Friday. However, People.com said the Grammy Award-winning recording artist was welcomed by cheering fans as she took the stage at the Mandela concert and sang her hit songs "Rehab" and "Valerie."
At the end of "Valerie, she bowed her head, stepped back toward the band and thanked the Soweto Gospel Choir, the entertainment news Web site said.
The concert was orchestrated to celebrate Mandela's birthday, as well as to help raise awareness for the former South African president's 46664 campaign and his other charity organizations.
"Our work is for freedom for all," People.com quoted Mandela as saying.