A randomized prospective study of 34 patients with IgA nephropathy and nephrotic syndrome was conducted to determine the therapeutic value of corticosteroid therapy. The patients were divided into two groups: Group A, 17 patients receiving oral prednisolone/prednisone for four months; and Group B, 17 patients receiving no corticosteroid therapy and acting as controls. The groups are comparable in age of presentation, sex ratio, and duration of study. No difference in serum creatinine levels, creatinine clearance, serum IgA levels, severity of renal histopathological changes, incidence of hypertension or incidence of impaired renal function could be demonstrated but the Group A patients had significantly heavier proteinuria. During the mean study period of 38 months (range 12-106), no significant difference in serum creatinine levels and creatinine clearance was demonstrated between the two groups. Forty percent of the Group A patients developed complications related to steroid therapy. Despite the overall lack of therapeutic value in IgA nephropathy with nephrotic syndrome as reflected by change in renal function, corticosteroid treatment resulted in excellent remission of nephrotic syndrome in 80% of patients with mild glomerular histopathological changes. Our findings suggest that corticosteroid therapy is only beneficial to selected groups of patients with IgA nephropathy and nephrotic syndrome but its indiscriminate use should be discouraged.