BACKGROUND: In Sweden heart failure is the most frequent discharge diagnosis within internal medicine. The prevalence of heart failure seems to be increasing, mainly due to an ageing population, but also because of improved survival in patients with cardiovascular diseases. AIM: To describe the epidemiology of heart failure in Sweden from a perspective based on demographic and health care data. METHODS: The national registers in Sweden provide detailed information on health care consumption in relation to different diagnoses. Pharmaceutical sales are also registered. There are national epidemiological reports, reports on health care utilization and on health economics concerning heart failure patients. RESULTS: There has been structural changes in the Swedish health care system due to financial restraints in the health care budget. Aiming at reducing hospital costs, the total amount of hospital beds has been cut down markedly during the last decade. The number of heart failure patients and the number of hospital stays have increased during the same period. Hospital stays have become shorter. The number of patients and hospital stays more than double when heart failure as both primary and secondary discharge diagnoses are included. CONCLUSION: The available national registers provide a good opportunity to study epidemiology of heart failure in Sweden. The number of hospital beds has decreased markedly within the last decade due to changes in the Swedish health care system. Nevertheless, there has been an increase in the number of patients discharged with heart failure from the hospitals, suggesting an increase in prevalence.