Fifteen elderly depressed psychiatric inpatients were randomly assigned to receive either standard three-times-weekly electroconvulsive therapy (ECT) or once-weekly ECT. Outcome measures included cognitive assessment and antidepressant response. Although both groups improved with treatment, the three-times-weekly group improved substantially more quickly. There was no difference in cognitive effect between the two groups. We conclude that the traditional three-times-weekly schedule of ECT may optimally balance speed of antidepressant response and cognitive impairment.