The actress appeared on stage for a waltz with Channing Tatum during the ceremony's opening skit, accompanied by host Seth MacFarlane singing 'The Way You Look Tonight'.
Theron has now admitted that she had no idea what she was signing up for when she agreed to the dance.
"I was sort of tricked into it," she told E! News. "I thought it was going to be something smaller, like he pulls me up from the audience and we do a little spin. But then he was like, 'Rehearsals start Monday!'"
Theron confessed that the performance was "completely nerve-wracking" but added: "How could I not dance with Channing Tatum? He's so wonderful!"
Earlier, Theron had attracted praise on the red carpet when she rushed to the aid of a security guard who collapsed while suffering a seizure.
Watch Seth MacFarlane's opening skit at the Oscars below:
Photo gallery - best- and worst-dressed at the Oscars:
Copyright: PA Images