Kok began his career with AJAX Amsterdam, playing for the Dutch club from 1967 until 1977. He then moved to K. Boom F.C. in Belgium and played there until 1978, when he signed for Lierse South.K. The following season, he moved to Switzerland with Football Club where he stayed until signing for Football Club in 1984.
In 1988, Football Club Zürich acquired his services. He finished his career in 1992, shortly after signing with Football Club Basel.