Renal involvement was studied in 70 patients with leprosy by urine analysis, detailed biochemical investigations and renal histopathology. Of these 70 patients, 40 had lepromatous and 30 had non-lepromatous leprosy. Creatinine clearance was reduced in 20 patients. Renal biopsies were studied in 50 cases (25 lepromatous, 25 non-lepromatous); of which in 13 cases (10 lepromatous, 3 non-lepromatous) abnormal histopathological lesions were found by light microscopy. Amyloidosis was seen in only one lepromatous patient. No acid-fast bacilli and leproma like lesion were demonstrated in any case.