Eighty patients with non-insulin-dependent diabetes mellitus being treated in a south Indian hospital were biopsied to confirm suspected nondiabetic renal disease (NDRD). The positive predictive value of the standard clinical indicators for NDRD in the presence or absence of diabetic retinopathy was 54 and 87%, respectively. These values are higher than those given by comparable studies in Western populations. This is probably due to a higher prevalence of NDRD in the population of south India, and especially of proliferative glomerulonephritis, which was found in 21.5% of the patients studied. Standard clinical predictors of NDRD in diabetics have a high predictive value in the tropics where there is a high prevalence of proliferative glomerulonephritis.