We describe here a patient with relapsed hepatoblastoma after LDLT who developed heart failure, which was treated with irinotecan hydrochloride (CPT-11). His native liver was replaced by a liver graft from his mother at 26 months from the onset. However, LDLT failed to induce complete remission and he was diagnosed as relapsed hepatoblastoma six months after LDLT. We again administered cisplatin and doxorubicin. After six courses of chemotherapy, he developed congestive heart failure because of anthracycline toxicity. The chemotherapy regimen was therefore switched to irinotecan at 35 mg/m2 daily for three days/wk for two consecutive weeks, and repeated every 28 days. After four courses of irinotecan, metastatic lesions were remarkably reduced in size, and the serum level of AFP decreased from 0.7 million to 927 ng/mL. No severe side effects were documented and congestive heart failure improved. These results suggest that irinotecan may be safely given to a patient with relapsed hepatoblastoma after LDLT without serious side effects and may contribute to prolonging the survival.