Eleven patients with tardive dyskinesia were treated in a double-blind study of vitamin E or placebo for 12 weeks. Abnormal Involuntary Movement Scale (AIMS) ratings were performed before and after treatment. Patients receiving vitamin E showed a significant reduction in their AIMS scale score, but patients receiving Placebo showed no significant change. Vitamin E had a helpful effect evert for patients whose tardive dyskinesia was mild and long-term.