Although a typical course of electroconvulsive therapy (ECT) consists of 6 to 12 treatments, remission of depression has rarely been reported after a single treatment. We present the case of a 25-year-old woman hospitalized for a major depressive episode and suicidality, in the context of bipolar 1 disorder, whose symptoms fully remitted with 1 ECT. We also review the literature on rapid response to ECT.