Hagman, best known for playing J.R. Ewing on "Dallas," is auctioning off memorabilia including cowboy hats and boots he wore on the hit TV show.
Also on the auction block: items from his work on "I Dream of Jeannie" and works of art, furniture and antiques.
"I had fun collecting it and I had fun owning it, but I just don't have the room for it," said Hagman. "I could keep it someplace, keep it in storage, but then when I die my kids would auction it off so I might as well get the money myself, you know."
Hagman is also selling memorabilia from his mother Mary Martin's work in the Broadway productions of "South Pacific," "The Sound of Music," and "Peter Pan."
The auction is scheduled for June 4.
