For major psychiatric disorders in which suicidality is often a symptom, electroconvulsive therapy (ECT) is an established, highly effective treatment. In fact, suicidal risk may be an indication for the use of ECT to treat those disorders. The authors present new data and review clinical experience that indicate that ECT often exerts a profound short-term beneficial effect on suicidality. Little, if any, evidence supports a long-term positive effect of ECT on suicide rates, especially if diagnostically heterogeneous groups are considered. However, patients may have been assigned ECT precisely because they were suicidal and, hence, these reports may represent underestimates. As a whole, the published reports are weakened by methodological shortcomings, such as lack of controls, weak design, and possible cohort effects. In fact, most studies were designed to examine the impact of ECT on mortality rates in general, and all but one study found reductions in overall mortality, the source of which remains undetermined.