E! News said Sheen's appearance came during Kimmel's interview with HDNet owner Mark Cuban Monday night. Cuban has said in the past he and Sheen are looking for a project to work on together.
During Cuban's chat with Kimmel, Sheen appeared onstage, kissed the talk-show host on the lips and handed out to the cheering audience T-shirts with some of his favorite expressions such as "winning" and "tiger blood," E! News said.
"I can't stay, sorry," Sheen told Kimmel and his viewers. "I have a show to write, dammit!"
Sheen, who recently was fired from TV's "Two and a Half Men" because of his erratic behavior, has announced plans for a touring stage show. Dates in New York, Boston, Detroit and Chicago have already sold out.