We treated 15 children with Sydenham's chorea with sodium valproate at a dose of 15 to 20 mg/kg/d. In 13 of them the chorieform movements disappeared within 1 week of therapy. The remaining 2 had incomplete response. Two patients relapsed; 1 of them responded to the reintroduction of valproate. The mean duration of treatment was 6.7 weeks. We observed no major side effects. This study strongly suggests that valproate is an effective drug in the treatment of Sydenham's chorea.