During the 1960s Ha Ui-Geon played basketball for the South Korean national team and competed at several international competitions. In 1964 Ha was part of the squad that played in the tournament at the Tokyo Olympics. The team, however, failed to win a single game, finishing 16th and last. He enjoyed better success in the years that followed, winning bronze at the 1966 Asian Games and silver at the 1967 Summer Universiade. He made his second and final appearance at the Olympics for the 1968 Mexico City Games where the team improved on their previous performance by winning two matches. Ha later worked as a banker but continued to have close ties with the sport, serving as the vice-chair of the Korea Basketball Association from 2006 until 2013.