Congestive heart failure (CHF) is a disorder characterized by a variety of clinical, biochemical, electrophysiological, and hemodynamic abnormalities. During the past two decades, numerous drugs have been employed in the treatment of this complex syndrome, and many agents have been shown to improve symptoms and ventricular function in patients with CHF. Because CHF is associated with a high risk of death, treatment should be directed not only toward the relief of symptoms, but also toward a reduction in mortality. Many variables have been shown to be related to survival; taken individually, however, each is limited in its utility in predicting prognosis. In recent years, large-scale studies with large sample sizes have directly assessed the effects of treatment on mortality in CHF. Results from these trials indicate that vasodilators and angiotensin-converting enzyme (ACE) inhibitors may improve mortality in patients with symptoms of heart failure. Additional trials are now in progress to evaluate the effect of treatment on patients with asymptomatic left ventricular dysfunction.