Thuc Thuân Thai took up judo at a young age and, in 1956, was one of the founding members of the Vietnamese Judo Association, which was the official judo federation for the Southern Republic of Vietnam. When judo was added to the Olympic program in 1964, he attended as a representative of South Vietnam in the middleweight division, where he lost his bouts against Pipat Singsanee of Thailand and Peter Snijders of the Netherlands and was thus eliminated from the competition. He later moved with his family to Southern California and spent the rest of his life there, teaching judo in the Los Angeles area.