Continuation and maintenance electroconvulsive therapy (ECT) are used to prevent relapse of depression after a successful course of index ECT. Such a course of treatment is typically extended for as long as a year. However, some patients seem to require longer courses of maintenance ECT. Little is known about the outcomes of long-term use (> 1 year) of maintenance ECT. We reviewed our maintenance ECT practice for the year 2000 and found that 43 patients had been receiving maintenance ECT for more than a year. This retrospective study reviews the outcomes of these patients. All patients had depression associated with either unipolar or bipolar disorder or schizoaffective disorder. These patients had multiple medication or psychotherapy trials or both and multiple hospitalizations before receiving maintenance ECT. Effects on depressive symptoms, level of functioning, health care use, frequency of hospitalizations, and cognition are discussed. We conclude that extended maintenance ECT is efficacious and well tolerated and reduces hospital use for a population of chronically depressed patients refractory to medication.