Increased septic complications with three-drug sequential immunosuppression for cadaver renal transplants. In 152 renal transplant recipients, the results of immunosuppression with three-drug sequential (Minnesota antilymphocyte globulin, prednisone, azathioprine, and cyclosporine) immunosuppression (n = 107) were compared with those of a two-drug sequential protocol (Minnesota antilymphocyte globulin, prednisone, and cyclosporine) that excluded azathioprine (n = 45). The study groups were comparable by age, sex, etiology of renal failure, incidence of diabetes, and degree of HLA matching. Patient survival at 1 year was not significantly different in the two groups (two drug, 93% versus three drug, 86%; p = 0.19). One-year graft survival was superior in the two-drug group (two drug, 93% versus three drug, 75%; p = 0.02). Analysis of primary transplants only (n = 116) yielded the same results. During the first year, the serum creatinine level remained stable in both groups. As expected, the three-drug therapy group had significantly more bacterial and viral infections. For low-risk primary cadaveric renal transplants, two-drug sequential immunosuppression is superior. 