We report on the prevalence of chronic heart failure (CHF) in a random sample of a population (aged 20-64 years) from the Veneto region in northern Italy. The relationship between CHF and hypertension and obesity was also investigated. These data were collected during an international research project coordinated by the World Health Organization. The overall prevalence of CHF was 2.0% both in the male and female population. The prevalence of CHF increased significantly with age and was positively correlated with body mass index in both sexes. Patients with borderline hypertension showed a 3.5-fold increased prevalence of CHF. The prevalence of CHF was 4.9-fold higher in hypertensive than in the normotensive subjects. Patients treated with hypotensive drugs had a significantly higher prevalence of CHF than untreated patients.