In return, the Blackhawks will receive a fourth-round draft pick in the 2006 NHL Entry Draft.
"Jocelyn is a class act and did a lot for our organization," Blackhawks GM Dale Tallon said. "We're happy to be able to get a deal done and we're happy that he's going to a good situation in Pittsburgh. He'll do quite well for them, we wish him all the best. It was strictly a business decision."
Thibault, 30, has a 227-217-68 record.
He was acquired by the Blackhawks along with Dave Manson and Brad Brown from Montreal in exchange for Jeff Hackett, Eric Weinrich, Alain Nasreddine and future considerations on Nov. 16, 1998.