Mediate turned professional in 1985. His golfing career has been marred by back trouble. Early on, he compensated by using a long putter. In 1991 he became the first player to win on the PGA Tour using a long putter when he won the Doral-Ryder Open. He picked up another victory at the 1993 KMart Greater Greensboro Open, but he then had a long layoff due to a ruptured disk. He underwent major back surgery in 1999, but lost practically five years of his career. Back pain returned in 2004 and later nearly ended his career.