Geographic/population variation in the prevalence of diabetic nephropathy is well recognised. In a study of 'native' Indians, we screened 102 non-proteinuric diabetes mellitus patients (64 NIDDM, 38 IDDM; mean age and diabetic duration 48.7 and 6.5 years, 21.6 and 6.2 years, respectively) with blood pressure less than or equal to 170/105 and without congestive heart failure, ketonuria or urinary tract infection, for the presence of microalbuminuria (albumin excretion rate greater than 20 micrograms/min). Fifty-six patients (34 NIDDM, 22 IDDM) also underwent detailed fundus examination. Seventeen NIDDM (26.6%) and 3 IDDM (7.9%) patients had microalbuminuria. Glycated hemoglobin was significantly higher in microalbuminurics in the NIDDM group (P less than 0.05). Diabetic retinopathy tended to occur more frequently in microalbuminurics (NIDDM and IDDM).