The aim of the study was to assess the total prevalence of obesity, non-insulin-dependent diabetes mellitus (NIDDM), hypertension, hypertriglyceridemia, hypercholesterolemia and central fat distribution, in a population-based survey. Two-hundred and ten individuals from the community were selected by random digit dialing. Obesity was defined as a body mass index > or = 25 kg/m2, central distribution of fat if the waist-to-hip ratio > 0.80 in women and 1.0 in men, diabetes was diagnosed if fasting plasma glucose levels > or = 140 mg/dl and/or currently under treatment, hypertension was defined as a systolic blood pressure > or = 140 mm Hg and/or diastolic blood pressure > 90 mm Hg and/or currently taking antihypertensive medications, hypertriglyceridemia was defined as a fasting serum triglyceride concentration > or = 200 mg/kg and hypercholesterolemia as a fasting serum cholesterol level > or = 200 mg/dl and/or currently taking specific medication. Prevalence rates of obesity, NIDDM, hypertension, hypertriglyceridemia, hypercholesterolemia and central fat distribution were 54.3%, 8.0%, 60.0%, 13.9%, 67.0% and 46.7% respectively. The prevalence of each of these conditions in its isolated form was 2.8% for obesity, 0.0% for diabetes, 3.8% for hypertension, 0.5% for hypertriglyceridaemia, 12.0% for hypercholesterolemia and 0.1% for the central fat distribution pattern. The large differences in prevalence between isolated and combined forms in the six disorders analyzed indicate a great overlap between these cardiovascular risk factors, and give epidemiologic support to a proposed metabolic syndrome.