We have adopted the use of an oral tacrolimus induction protocol in pediatric liver transplantation since the commercial release of tacrolimus in 1994. In this study we analyzed the efficacy of oral tacrolimus induction therapy in 17 consecutive transplants (15 patients) performed between 6/94 and 2/95 and 4 additional patients who were retransplanted between 11/93-5/94 and received compassionate oral tacrolimus induction. Sixteen transplants were treated with oral tacrolimus induction only; 5 transplants, oral tacrolimus + ATGAM/OKT3 induction. The protocol consisted of 0.2 mg/kg of tacrolimus orally on the first postoperative day with a corticosteroid taper. Oral tacrolimus was started at day 1-8 in the 5 patients receiving ATGAM/OKT3 induction. Dosages were adjusted over time to maintain a whole-blood trough level of 12-15 ng/ml at 0-1 month, 10-12 ng/ml at 1-3 months, and 5-10 ng/ml after 3 months. The incidence of acute rejection was 50% (8/16) in children on oral tacrolimus induction alone and 80% (4/5) in the tacrolimus + ATGAM/OKT3 group. Epstein-Barr virus infection occurred in 6 of 19 children (32%), with no child developing lymphoproliferative disorder. No adverse effect on renal function was noted. Serum fasting glucose was stable over time while a trend was noted in decreasing serum cholesterol levels at 6 months. Antihypertensive medication was required in 4 of 19 children (21%) posttransplantation. Corticosteroids were withdrawn in 11% (2/19) of patients. Actuarial 1-year patient and graft survivals were 95% and 86%, respectively. The use of oral tacrolimus induction therapy was associated with excellent survival and a low incidence of complications.