Of all persons aged over 40 years, approximately 1% have heart failure. The prevalence of heart failure doubles with each decade of life, and is around 10% in persons over 70 years of age. In Spain, heart failure causes nearly 80,000 hospital admissions every year. As in other developed countries, heart failure is the most frequent cause of hospitalization among persons 65 years of age and over, and is responsible for 5% of all hospitalizations. The incidence of heart failure increases with age, and reaches 1% per year in those over 65. Heart failure is a progressive, lethal disorder, even with adequate treatment. Five-year survival is around 50%, which is no better than that for many cancers. In Spain, heart failure is the third leading cause of cardiovascular mortality, after coronary disease and stroke. In 2000, heart failure caused 4% of all deaths and 10% of cardiovascular deaths in men; the corresponding figures for women were 8% and 18%. In recent decades the prevalence and number of hospitalizations due to heart failure have increased steadily in developed countries. Heart failure will probably continue to increase in coming years: although its incidence has not materially decreased, survival is increasing due to better treatment. The control of risk factors for hypertension and ischemic heart disease, the main causes of heart failure in Spain, is the only method to halt the foreseeable increase in heart failure in the near future.