A 14%, simple random sample of the King Saud University Community consisting of students, faculty and staff was screened for diabetes mellitus. The screening procedures used consisted of urine testing by means of the urine dipstick and blood glucose estimation in the fasting state by means of the reflomat glucose, a glucose oxidase meter. Participants whose fasting blood glucose (FBG) were 140 mg/dl or more were referred to the diabetes clinic for further evaluation and possible inclusion into the subsequent retrospective study. A period prevalence of 6.0% was observed for FBG greater than 140 mg/dl and all the referrals were confirmed for adult onset diabetes mellitus. The prevalence was similar to that in the USA and suggested that the rapid socio-economic changes in Saudi Arabia made a minimal contribution to the prevalence of diabetes mellitus.