Aripiprazole, a partial dopamine agonist has been reported to help reduce symptoms of tardive dyskinesia (TD). In a prospective, open label study of a series of cases, we examined the effectiveness of aripiprazole in reducing TD symptoms. Six clinically stable patients with schizophrenia or Schizoaffective disorder and a moderate to severe TD participated in this study. They were systematically cross-titrated from their current medication to aripiprazole and maintained for 16 weeks. The mean extra pyramidal symptom score measured by Abnormal Involuntary Movement Scale (AIMS) improved from a baseline score of 15.8 to final score of 5 (paired t-test; P=0.0009). The severity of psychiatric symptoms remained unchanged. This study supports our hypothesis that clinically stable patients with moderate tardive dyskinesia who are under treatment with other first- or second-generation antipsychotics may benefit from switching to aripiprazole with a reduction of TD symptoms but with out any significant benefit in psychiatric symptoms. The results need to be viewed with caution and not considered as indicative of a viable treatment option for TD as this is an open label study, and a small sample size.