South Africans need not be concerned about ANC leader Jacob Zuma's low level of formal education, former opposition leader Tony Leon said on Tuesday.

"There is much concern about the fact that the next president of South Africa only has primary school education," Leon told a leadership conference in Sandton, Johannesburg.

"There might be other reasons to express concern about the next president, but actually his educational disadvantage seems to be utterly irrelevant."

Leon, the former leader of the Democratic Alliance, said "character overcomes qualification".

He cited examples of several international leaders who were successful despite a lack of academic qualification, including once US president Harry Truman and former British prime ministers Winston Churchill and John Major.

"All these men, like Zuma incidentally, actually were comfortable in their own skin. They were people who knew themselves and their limitations and therefore they were able to make the right judgement calls," said Leon.

But he added: "I have no idea whether the next president of South Africa will fulfil this requirement."