Artist Brett Murray's controversial painting showing Zuma with his fly open and penis exposed, sold for R136 000 at the Goodman Gallery in Johannesburg.
ANC spokesperson Jackson Mthembu said the "disgusting and unfortunate display of the president" is insulting, and the party is taking the matter to court.
"We have this morning [on Thursday] instructed our lawyers to approach our courts to compel Brett Murray and Goodman Gallery to remove the portrait from display as well as from their website and destroy all printed promotional material.
"We have also detected that this distasteful and vulgar portrait of the president has been displayed on a weekend newspaper and its website, we again have instructed our lawyers to request the said newspaper to remove the portrait from their website."
Murray's so-called piece of art dents the image and the dignity of Zuma as both president of the ANC, president of the republic and as a human being, Mthembu said.
The ANC also took exception to a second portrait, which displays the party's logo "without the permission of the ANC", with the inscription "FOR SALE" on it.
"Both these portraits are a clear calculation to dismember and denigrate the symbols and the representative of the ANC, chief amongst them, the president of the ANC."
Mthembu said the ANC believes in both freedom of the press and artistic expression, but views "the vulgar portrait and the dismembering of the ANC logo by Brett Murray an abuse of freedom of artistic expression and an acute violation of our constitution, apart from being defamatory".
"That is why we have instructed our lawyers to approach the courts in-view of these violations and the defaming nature of the so-called President Zuma portrait titled The Spear," he said.