Nearly five million people in South Africa are totally illiterate, Education Minister Naledi Pandor said on Monday.
Another 4,9 million South Africans were functionally illiterate - people who had dropped out of school before Grade Seven.
Pandor said the figures were compiled by a ministerial committee she appointed to help find the best way to tackle illiteracy.
Pandor said 4,7-million people were regarded as totally illiterate because they had never attended school.
The committee had proposed the department first focused on those who were totally illiterate.
"How do you eat an elephant? The answer traditionally has been: bit by bit," said Pandor. "However, a ministerial committee has provided me with a plan that poses to eat the elephant whole, then moving on to the next one, whole."
She said R6-billion would be spent in a bid to eradicate total illiteracy. Only then would functional illiteracy be taken on.
The plan was likely to stretch over five years from 2007 to 2012, and would seek to equip totally illiterate students with basic sustainable literacy.
Pandor said KwaZulu-Natal, the Eastern Cape and Limpopo were identified as the provinces most affected by illiteracy.
"KwaZulu-Natal has 1,1 million adults with no schooling and another one million who are functionally illiterate."
Those most affected came from language groups such as isiZulu, isiXhosa and sePedi.
South Africa's second attempt to eradicate illiteracy would this time around delve into Cuba's reformed education system, she said.
"I have been particularly impressed by the Cuban education system... Not only did Cuba develop a successful plan for tackling illiteracy, but Cuba also now has an enviable record of learner achievement - it outscores every Latin American country in international assessments, and, according to Unesco (the United Nations Educational Scientific and Cultural Organisation), many European and Asian ones as well."