The veteran game-show host, who helmed "The Price is Right" from 1972 to 2007, was invited back by current host Drew Carey on Thursday to celebrate the milestone birthday.
The audience gave Barker a standing ovation. He moved a little more slowly, and his microphone was a little thicker, but he fell right back into the groove.
During the appearance, Barker showed off a puppy that was available for adoption, and presented a special showcase.
He also joined with Carey in encouraging viewers to spay or neuter their pets -- Barker's longtime cause.
To the reception, he said, "You folks appreciate the fact that it has taken me a long time to become 90."