He was a member of Korean national football team for five years in the 1970s. He played in the 1974 FIFA World Cup qualifying match against Australia, scoring the equalizing goal. A training injury to his knee ended his playing career.
His first managerial post a was at his alma mater, Joongdong High School. Under his management, the Joongdong team flourished and won many honours.[which?] Ko Jae-Wook joined Lucky-Goldstar Hwangso as coach in 1984, and was appointed manager in 1989. Ko achieved immediate success with Lucky-Goldstar Hwangso by winning the 1990 K-League title. He was appointed manager of Ulsan Hyundai Horangi in December 1994. In his second season (1996), Ulsan Hyundai Horang-i won the K-League title.