The frequency of sessions during a course of electroconvulsive therapy (ECT) is a topic of considerable interest for the practicing psychiatrist. In this narrative review, we examine the practice of and evidence-base for different schedules of ECT administration. A reasonable level of evidence is available to suggest that ECT administered twice weekly seems to have the best balance between therapeutic outcome and adverse effects in the immediate treatment of major depressive disorder while using bilateral ECT. Evidence also suggests that increasing the frequency of ECT may result in more rapid improvement of depression, but it increases adverse cognitive effects. However, very few data exist for comparing the merits and demerits of different frequencies of ECT administration during the immediate treatment of other disorders. There is also lack of research evidence to guide psychiatrists in deciding on the frequency of ECT administration during the continuation and maintenance phases.