According to a government statement, Mr Mandela was treated for a long-standing abdominal complaint and is expected to be discharged from hospital tomorrow. It added that the anti-apartheid icon, 93, is comfortable and “fully conscious.”
He has suffered declining health in recent years.
In the statement, President Jacob Zuma’s office said the “love and good wishes of all South Africans and people throughout the world” were with Mr Mandela, and asked for his family to be given privacy.
The statement did not say which hospital he had been admitted to but there are suggestions it was a military hospital in the capital, Pretoria.
Mr Mandela had returned to Johannesburg last month from his rural home in the Eastern Cape and in January last year, he received treatment in the city’s Milpark hospital for a serious chest infection.
“I can assure you that the former president is in good spirits and well,” said Mac Maharaj, a spokesman for Mr Zuma.