Diabetes mellitus, hypertension and obesity are among the multifactorial disorders that occur at a higher prevalence in older age groups. Their prevalence is affected by both genetic and environmental factors. We investigated the distribution of diabetes mellitus, hypertension and obesity in Saudi males and females by conducting a household screening survey during the period 1992-1996 of the adult population (> 14 years) in five different areas of Saudi Arabia. Height, weight, age and other essential details were recorded and diastolic and systolic blood pressures measured. Glucose levels were measured in blood taken after fasting and 2 hours after a glucose load. The data were used to classify the individuals as diabetic, glucose intolerant and normal, using WHO criteria. The individuals were further classified as type 1 diabetes mellitus and type 2 diabetes mellitus. The overall prevalence of diabetes mellitus was 9.7% and 7.0%, obesity 13.05% and 20.26%, overweight 27.23% and 25.20%, and hypertension 5.39% and 3.65% in the adult male and female populations respectively. A significant increase was observed in the prevalence of diabetes, obesity and hypertension with age in both males and females. In addition, the prevalence of obesity and overweight was significantly higher in the individuals with diabetes mellitus.