Renal involvement was studied in 538 consecutive NIDDM subjects (271 males and 267 females). The mean (SD) age of males was 55.4 (11.0) and of females 51.0 (10.5). Diabetic nephropathy was present in 8.9 per cent of the patients (urinary albumin excretion greater than 200 micrograms/min) and another 19.7 per cent had microalbuminuria (20-200 micrograms/min). Male predominance was striking in the macroalbuminuric group (P less than 0.001). The age of the patients and duration of diabetes in patients with micro and macroalbuminuria were significantly higher as compared to those in normoalbuminuric group (P less than 0.001). Patients with micro and macroalbuminuria had significantly elevated blood sugars and blood pressures (P less than 0.01). The prevalence of vascular complications were found to be higher in the macroalbuminuric group (P less than 0.01). Male sex, older age, longer duration of diabetes, poor glycaemic control and raised blood pressure were significant risk factors in the development of diabetic nephropathy.