In order to evaluate whether immunosuppressive agents such as mycophenolate mofetil (MMF) and azathioprine would differently influence the outcome of the renal transplants, we prospectively analyzed the incidence of acute rejection episodes, cytomegalovirus infection within the first 6 months following renal transplantation and 5 yr graft survival rate after minimizing influences of donor factors by grafting the same cadaveric donor kidney. There was no significant difference in sex, HLA mismatch, cold ischemic time, and patients' weight between the two groups. Contrary to the previous studies which demonstrated that MMF could lower the incidence of acute rejection episodes and improved graft survival rate, the two groups showed no significant difference in the incidence of acute rejection episodes and 5-yr graft survival rate as well. This discrepancy in these results might explain that donor factors could be important to cadaveric renal transplantation. Thus, we suggest that the influences of donor factors should be considered in further clinical studies of cadaveric renal transplantation.