This report concerns the long-term outcome of living donor liver transplantation (LDLT) for pediatric patients at a single center. Between June 1990 and December 2003, a total of 600 LDLTs, including 568 primary transplantations and 32 retransplantations, were performed for pediatric patients, who were immunosuppressed with FK506 and low-dose corticosteroids. Patient survival at 1, 5, and 10 years were 84.6%, 82.4%, and 77.2%, respectively, and the corresponding findings for graft survivals were 84.1%, 80.9%, and 74.5%. Multivariate analysis demonstrated that fulminant hepatic failure (FHF), a graft vs. body weight (GBWR) ratio of Ͻ0.8, and ABO-incompatible transplants were independently associated with both patient and graft survival. The retransplantation rate was 6%, and 55 patients (9.7%) have been completely weaned off immunosuppressants. Long-term patient and graft survival after pediatric LDLT for a large cohort of children at our hospital were found to be as good as those for cadaveric liver transplantation, although this series includes 13% liver transplantations with ABO-incompatible donors, which are obviously inferior in patient and graft survival. To obtain better outcomes for patients with FHF and for patients with ABO-incompatible transplants, immunosuppressive therapy needs to be improved. Liver Before the 1990s, many patients in Japan with endstage liver diseases used to die without the therapeutic option of liver transplantation (LT). Because organ transplantation from deceased donors was prohibited by law, we conceived of the possibility that LT from living donors could be an alternative. Even with the donor's safety as the first priority, transplantation of the lateral segment grafts was considered feasible because lateral segmentectomy of the liver was a wellestablished and safe procedure. In addition, it was hypothesized that living donor liver transplantation (LDLT) for children with their parents as donors might yield better results, both in the short and long term, for graft acceptance compared with livers taken from cadavers because of the superior viability of the living donor's organ, thus requiring a shorter cold ischemic interval and good histocompatibility leukocyte antigen match between parent and child. After the first successful cases of LDLT in 1990, 1 this revolutionary procedure was adopted throughout Japan as an effective therapy for children with end-stage liver disease. Here we report the long-term results of pediatric LDLT at a single center over the last 14 years.