Nelson Mandela has successfully undergone surgery to have gall stones removed.
A government statement said the operation was successful and Mr Mandela is recovering.
Mr Mandela, 94, was admitted to hospital last Saturday after a recurrence of a lung infection.
The BBC reports tests revealed the presence of gallstones and doctors treating Mr Mandela decided to remove them once he had recovered from the infection.
The statement said:
"This morning, 15 December, 2012, the former president underwent a procedure via endoscopy to have the gall stones removed. The procedure was successful and (Mr Mandela) is recovering."
Mr Mandela led the struggle against white-minority rule under apartheid before being elected the first black president in 1994.
Despite being imprisoned for 27 years, he forgave his former enemies and urged South Africans of all races to work together and seek reconciliation.
He was awarded the Nobel Peace Prize in 1993.