The psychiatric literature generally discourages the use of electroconvulsive therapy (ECT) to treat depression in dissociative disorder patients, but contains little data on outcome. This prospective study of ECT in three dissociative disorder patients demonstrates that ECT is indicated for severe treatment-resistant depression in such patients. Their Hamilton Depression Scale scores fell by 50%, they were remarkably clinically improved, and they maintained their gains for at least 4 months. The ECT proved helpful when depression was felt by most of the active alters rather than just by one depressed personality. Mini-Mental State Examination scores and clinical observation revealed no unusual confusion or side effects from ECT. These patients' dissociated condition was not altered by ECT, which indicates that ECT neither treats nor impairs treatment of dissociation. Electroconvulsive therapy can be helpful in the overall treatment of dissociative disorders by alleviating severe depressions which block utilization of psychotherapy.