Seven patients with bipolar disorder, characterized by dysphoric mania with psychotic features and chronic disability, refractory to standard treatments and anticonvulsants, all showed marked symptomatic and functional improvement when given the atypical antipsychotic clozapine. During follow-up over 3-5 years, most of the patients sustained substantial gains in psychosocial function; and of the six patients remaining on clozapine, no further hospitalizations were needed. This remarkable improvement in a severely ill group of patients suggests that clozapine may have utility in the treatment of bipolar disorder as well as schizophrenia.