After good performances with Marseille in France, the young defender was included in the 23-man roster for the 2002 World Cup in South Korea and Japan. He played the full game in Belgium's opening match of the tournament, a 2–2 draw with co-hosts Japan on 4 June. In the second group match, Belgium stuttered to a surprising 1–1 draw with Tunisia on 10 June while Van Buyten booked for the Belgians. Van Buyten helped Belgium pick up their first win of the tournament and in doing so progression to the knockout stage, stopping a late flurry from Russia to secure a 3–2 victory. Finishing as runners-up in the group, Belgium were dealt a tough draw with four-time champions Brazil. Despite a valiant effort, Van Buyten and the Belgians bowed out in the round of 16 as the duo of Rivaldo and Ronaldo led Brazil to a 2–0 win. The South Americans would eventually be crowned champions with a defeat of Germany in the final on 30 June by the same scoreline.