In attempt to avoid a detrimental synergism between CsA and renal ischemia in the immediate postoperative period, ALG (425 lymphocytotoxic units/kg) with small doses of CsA (6-8 mg/kg) and P were applied as the initial immunosuppressive therapy in 14 recipients of cadaveric kidneys. ALG was administered for 5 to 14 days and 2 days before withdrawing ALG, Aza (2 mg/kg) was introduced. Results of this protocol were compared with those of 19 pts treated with CsA (12 mg/kg) and P. All the pts were followed for at least 12 months. The duration of posttransplant anuria was significantly reduced in the ALG/CsA/P group (p < 0.02). The sCr concentration after 12 months of observation was significantly lower (p < 0.05), no alterations in urinalysis were detected, the number of hypertensive pts was decreased. The acute rejection rates were equivalent in both groups, however 3 of 4 rejections in ALG/CsA/P group were resistant to steroids and occurred in pts with shortened period of ALG administration. The one year patient and graft survival in the ALG/CsA/P and control groups were respectively: 78.5%, 71.4% and 89.4%, 78.9%. Severe infectious complications in the group treated with ALG/CsA/P occurred in pts who were subsequently treated with OKT3.