Health scare: Nelson Mandela was being
treated for an 'abdominal complaint' today
In May he was given special dispensation to vote early in South Africa's elections amid fears for his condition.
A statement from the South African presidency said today: 'President Jacob Zuma wishes to advise that former President Nelson Mandela was admitted to hospital today.
'Madiba has had a long-standing abdominal complaint and doctors feel it needs proper specialist medical attention. 'We wish him a speedy recovery and assure him of the love and good wishes of all South Africans and people throughout the world. 'We request that all respect the privacy of Madiba and that of his family during this period.'
Mac Maharaj, Mr Zuma's spokesman, said he could not elaborate but that he would be issuing regular updates.
Mr Mandela's hospitalisation has sparked increased speculation about his health. He stepped down fully from public life in 2004.
He became South Africa's first black president in 1994 after spending 27 years in prison for his fight against racist apartheid rule, and was awarded a Nobel Peace Prize for his efforts.
In 2001 Mr Mandela underwent radiotherapy for prostate cancer but was later given the all-clear by doctors.
Despite his age, the former president remains South Africa's most significant political figure.