Judges overturned an earlier high court ruling dismissing charges against Mr Zuma, saying the judge had “overstepped” his authority.
Prosecutors can now reinstate the charges, which Mr Zuma denies.
The ANC says Mr Zuma will still lead the party into this year’s polls, so he is likely to become the next president.
The 16 charges of corruption, money-laundering and racketeering stem from a controversial $5bn 1999 arms deal.
The ANC said that while it respected the Bloemfontein appeals court ruling, “it is important to note that this judgement has nothing to do with the guilt or otherwise of the ANC president. Nor does it make any pronouncements on the merits of the charges previously brought by the NPA [National Prosecuting Authority].”
Mr Zuma has said he would only resign from public office if convicted. He could still be prosecuted if he became president.
Political interference?
The charges against Mr Zuma were dismissed on a technicality last September.
But the Supreme Court said Judge Chris Nicholson in the High Court “overstepped the limits of its authority” by suggesting there may have been political interference in the prosecution of Mr Zuma.
Judge Louis Harms said the claims “were not based on any evidence or allegation. They were instead part of the judge’s own conspiracy theory and not one advanced by Mr Zuma.”
The suggestion of political interference led Thabo Mbeki to stand down as president. He was replaced by Kgalema Motlanthe, an ally of the ANC leader.
Mr Zuma has unwavering support from the ANC leadership, the trade union confederation Cosatu, the SA Communist Party, the ANC Youth League, the Young Communist League and the MK (Umkhonto we Sizwe) Veterans’ Association.
Mr Zuma’s supporters say the charges were part of a plot to prevent him becoming president.
For several years, the shadow of corruption has been hanging over Mr Zuma, who won a bitter ANC leadership contest against Mr Mbeki last year.
In 2005, Mr Zuma was sacked as South Africa’s deputy president when his financial adviser, Schabir Shaik, was found guilty of soliciting a bribe on behalf of Mr Zuma and jailed for 15 years in connection with the arms deal.
Mr Zuma then went on trial, but that case collapsed in 2006 when the prosecution said it was not ready to proceed.
He was also charged with rape, but acquitted in 2006.
BBC NEWS, 12 January 2009