Long term use of steroid induces multiple side effects and morbidity. However, SW has been reported to be associated with increased incidence of acute and chronic rejection, and subsequently reduced graft outcome. MMF inhibits the proliferation and functions of lymphocytes, decreases the incidence of acute rejection in organ transplants, and therefore may decrease the graft rejection associated with SW. We tried to withdraw steroid from 21 renal transplants treated with prednisolone and cyclosporine, who had clinically significant steroid induced side effects. Reasons for SW were diabetes in 15 patients (pre-transplant DM 4 and post-transplant 11), moon face 4 and avascular necrosis of femur 2. Prednisolone was tapered at a rate of 2.5mg every 2 weeks and was discontinued. MMF, 1.0-2.0g/day, was initiated at the beginning of SW. The time interval between transplantation and SW was 26+/-5 (1.5-67) months. Mean age was 48(28-61). Two patients developed MMF-induced GI side effects, and were returned to previous immuno- suppressants. In 1 patient, serum creatinine increased during SW, and steroid was re-administered with the restoration of renal function. In 18(86%) of 21 patients, therefore, steroid was successfully with-drawn. At the follow up of 17+/-1(13-24) months after SW, 1 patient with drug incompliance developed chronic rejection. The rest showed stable renal function. Steroid can be safely withdrawn from renal transplants by simultaneous administration of MMF. The long-term safety, however, needs to be evaluated by prolonged follow up studies.