OBJECTIVE: Overweight, particularly obesity is a major risk factor for several important diseases, especially hypertension, coronary heart diseases and diabetes mellitus. Our aim is to determine the prevalence of obesity and central obesity among Omani adults aged > or =20 years, and to identify the socio-demographic and health variables that correlate to obesity and central obesity in a community based survey (National Health Survey, 2000). METHODS: A community based cross-sectional survey representing all parts of Oman was designed in the year 2000. A part of the survey was a door to door interviews including demographic data, weight, height, hip and waist measurements, blood pressure and fasting blood glucose and serum cholesterol for adults aged > or =20 years. RESULTS: The crude prevalence of overweight and obesity (body mass index >25 kg/m2) was 47.9% for the whole sample, and 46.2% for males, 49.5% for females. The crude prevalence of central obesity (abnormal weight hips ratio) was 49.3% for the whole sample, 31.5% for males, and 64.6% for females. Obesity and central obesity were less prevalent among younger age groups and highly educated subjects. Both obesity and central obesity increased the odds of having diabetes, hypertension and hyperchlostremiCONCLUSION: The prevalence of obesity and central obesity is quietly high in Oman. Launching nutritional programs and promotional life style modification programs are recommended.