ABO-incompatible (ABO-I) living donor liver transplantation (LDLT) has been performed in Japan to overcome the organ shortage. Reported herein are the results of this approach through March 2006 in the National Registry of the Japan Study Group for ABO-incompatible transplantation. The questionnaires consisted of patient characteristics, operative data, and strategies for preventing antibody-mediated rejection (AMR). Data of 291 patients (follow-up period, 8 months-15 years; mean, 35 months) from 28 institutions were collected. Age was younger than I year in 68 patients, 1 to 7 years in 60 patients, 8 to 15 years in 27 patients, and 16 years or older in 136 patients. The strategy for the blood-type barrier was heterogeneous in terms of recipient age, transplant center, and era. Local infusion and rituximab prophylaxis were applied in 2000 and 2003, respectively. The 5-year patient survival rate was 85% in infants and 52% in adults. The major causes of death were infection and antibody mediated rejection (AMR). Multivariate analysis showed that age group, preoperative condition, antibody titer, and infection significantly affected survival. Age group, antibody titer, and local infusion treatment significantly affected the incidence of AMR. Patient survival rates were significantly higher and the incidence of AMR was significantly lower in adult patients after 2000 (3 year-survival rate, 29%, 56%, and 61%; incidence of AMR, 47%,27%, and 16%, through May 2000, from June 2000 through October 2003, and from November 2003, respectively). Conclusion: ABO-incompatible LDLT is a standard practice in children, and local infusion and rituximab prophylaxis are promising in adults.