After retirement, Okada started coaching career at Furukawa Electric (later "JEF United Ichihara") in 1990. In 1995, he became an assistant coach for Japan national team. During 1998 World Cup qualification in October 1997, Japan's manager Shu Kamo was sacked and Okada named new manager. In November, Okada led Japan to won qualify for 1998 World Cup first time in Japan's history. At 1998 World Cup, Japan lost all 3 matches and he resigned after the World Cup.