Heart failure is emerging as a major component of the public health problem of cardiovascular disease as we move into the twenty-first century. Current statistics indicate 4.9 million US citizens are afflicted with direct treatment costs estimated to be $18.8 billion per year. These figures are expected to worsen substantially as the prevalence of heart failure continues to increase. Epidemiologic studies also point to important increases in morbidity and have identified risk factors that aid in prognosis and that may contribute to our mechanistic understanding of heart failure pathophysiology. In addition, epidemiologic results indicate that many patients with mild-to-moderate clinical heart failure are still at substantial risk for morbidity and mortality during follow-up periods of only a few years. These data highlight the importance of enhancing physician and public awareness of heart failure. New methods of molecular epidemiology will point toward better and earlier detection of this common and frequently fatal condition.