OBJECTIVE--To assess the prevalence of diabetes and impaired glucose tolerance (IGT) in the urban and rural elderly population in south India. RESEARCH DESIGN AND METHODS--Urban and rural populations > or = 60 years of age and representative of the areas (873 urban and 588 rural subjects) were screened for diabetes and IGT using fasting and 2-h postglucose capillary blood glucose measurements. RESULTS--In the urban area, 211 (23.7%) had diabetes, and 101 (12.4%) had IGT. In the rural area, 56 (9.9%) had diabetes, and 82 (14.9%) had IGT. The ratio of newly diagnosed to known diabetes was 1:3 in the urban and 1:1 in the rural areas. Positive family history of diabetes, body mass index (BMI), subscapular-to-triceps ratio, and waist-to-hip ratio were significantly associated with diabetes in the urban population. Only age and BMI showed significant association with diabetes in the elderly rural population. None of the tested parameters, except age in the urban subjects, showed association with IGT. CONCLUSIONS--This study highlights the high prevalence of glucose intolerance in elderly south Indians having low mean BMI (mean +/- SD; urban 21.7 +/- 4.6, rural 17.9 +/- 3.3 kg/m2). Although there was a twofold higher prevalence of diabetes in the urban area, the occurrence of IGT was similar in urban and rural populations.