Complete resection of a rare hepatoblastoma in the caudate lobe, involving the inferior vena cava (IVC), is reported. After systemic chemotherapy, a 5-year-old child underwent exploratory laparotomy at another hospital, but resection was not attempted because the tumor in the caudate lobe had extensively invaded the retrohepatic IVC. However, because not only the lack of distant metastases but also the establishment of extrahepatic collaterals were confirmed by imaging, we thought it was possible to radically resect the tumor. We successfully performed an extended left hepatic lobectomy including total excision of the caudate lobe and the involved portion of the IVC. Although we did not reconstruct the IVC, no clinical manifestations arising from caval congestion were seen. The serum alpha-fetoprotein value declined below the normal limit. Our experience with this case has introduced a radical resectability for hepatic malignancy in the caudate lobe, even if it has extended into the IVC.