Mortality in congestive heart failure (CHF) usually occurs from either progressive worsening of cardiac pump failure or sudden cardiac death (SCD). Medical interventions that counter neurohormonal changes slow the progression of CHF and also prevent SCD. The benefits of medical therapy on SCD prevention have been variable, depending on the type of medical therapy. This article discusses the incidence, prediction, and prevention of SCD in CHF due to ischemic and nonischemic cardiomyopathy.