Tacrolimus is a superior immunosuppressive agent in patients undergoing renal transplantation. In adults, the 1- and 3-year actuarial patient survivals were 95% and 92%, and the 1- and 3-year actuarial graft survivals were 89% and 80%. For first cadaver kidneys, the 1- and 3-year actuarial graft survivals were 91% and 82%, with a projected half-life of 11.9 years. Sixty-nine percent of successfully transplanted patients were weaned off steroids. In pediatric patients, the 1- and 4-year actuarial patient survivals were 100% and 96%, and the 1- and 4-year actuarial graft survivals were 99% and 85%. Seventy-three percent of successfully transplanted children were weaned off steroids. Tacrolimus was also useful as a rescue agent, with an initial success rate of 74%. Tacrolimus has been used successfully in kidney/ pancreas transplantation, with 100% patient, 95% kidney, and 79% pancreas graft survival. Tacrolimus should be considered the immunosuppressive agent of choice in renal transplantation.