In 1997 he became manager of Willem II. The team finished in fifth place and had wins over Feyenoord (2–0) and defending champions PSV (4–1). The fifth place was the first qualification for European football since 1963. In the 1998–99 UEFA Cup they reached round 2 but lost to Betis Sevilla. After the team did not reach another European competition, Adriaans resigned in 2000.