When he was in high school Fumio Saito initially played baseball before switching to basketball. Saito then attended Chuo University in Tokyo, where he was selected to represent the All-Japan team in 1974. In addition to representing Japan at the Asian Games, he was also part of the squad that competed at the 1976 Montréal Olympics. Saito graduated from university a year later, with him then winning the Japanese league title with Matsushita Electric Industrial. He later returned to Chuo University, where he worked as a coach.