Walker played college basketball at the University of Kentucky. He won the 1989 NBA Slam Dunk Contest, competing three days after the passing of his father. He later played basketball over in Spain, Italy and Japan before retiring back in the United States. As a publicity stunt, Walker once raced against a horse, and won. On August 14, 1986, at New York's Monticello Raceway, Walker and harness racehorse "Pugwash" ran against each other over one-sixteenth of a mile in 10.4 seconds.