Despite the paucity of epidemiologic work on congestive heart failure (CHF), the salient features of the natural course of cardiac failure are understood. The estimated 1983 incidence of CHF in the United States was 214,000 men and 184,000 women. The estimate of prevalence was 2.3 million persons, with a remarkable increase with advancing age and higher rates in men than women at all ages. Overt heart disease plus age are the principal determinants of the incidence of CHF. Nearly 90% of patients with CHF have systemic hypertension or coronary heart disease, or both, as the antecedent underlying condition. Diabetes mellitus increases the risk of CHF at all ages, particularly in women and those treated with insulin. The prognosis after diagnosis of CHF is grim and is related to the degree of myocardial dysfunction. The challenge is to develop more effective drugs not only for the management of overt CHF, but also for the prevention of its progression.