The frequency of nephrotic syndrome was 0.2% of all medical admission records. A prospective study of 180 nephrotic patients was begun in 1966 and ended in 1976 and the clinical, biochemical and renal histological changes were studied. Unlike other studies of nephrotic syndrome in West and East Africa, in which malaria is believed to play an important aetiological part, this study in Durban was done in a malaria-free area. Most of the patients were between the ages of 12 and 30 years. The aetiology of the nephrotic syndrome was undetermined in 94% of the African patients and in 87% of the Indian patients. The most common histological pattern in both racial groups was proliferative glomerulonephritis, followed by membranous glomerulonephritis. Minimal change on light microscopy was rare. This has important implications from the therapeutic aspect because African patients suffering from nephrotic syndrome will not as a rule respond to steroids or cyclophosphamide therapy. An initial diastolic blood pressure greater than or equal to 110 mm Hg and a low serum complement were more common in proliferative glomerulonephritis. The serum gamma-globulin, though low, was raised compared with the normal serum gamma-globulin, in the white population. A difference in the serum lipoprotein patient between the two races was observed.