We encountered a 12-year-old girl with acute promyelocytic leukemia (APL) that occurred 21 months after a living donor partial orthotopic liver transplantation from her father for ornithine transcarbamylase deficiency. FK-506 had been administered for prophylaxis against graft-versus-host reaction. The bone marrow specimen revealed a massive infiltration of promyelocytic blasts (M3 by FAB classification) with chromosome 46, XX, t (15; 17) (q22; q12), being the recipient origin. A PML/RAR alpha chimeric gene was detected by RT-PCR. The patient was diagnosed as having APL and successfully induced to complete remission by chemotherapy including daunorubicin (DNR), cytarabine (araC), and all-trans retinoic acid (ATRA). She has been in continuous remission for 12 months after the treatment. Leukemia after liver transplantation is generally taken as a rare complication. However, recent advances in the survival rate of patients who have undergone liver transplantation will lead to an increase of such cases.