The clinico-pathological features of four cases of pediatric hepatic angiosarcomas are described. One case was initially diagnosed in infancy and underwent resection of a left-sided benign hemangioendothelioma of the liver. Further resection of a lesion in the right liver was followed by malignant transformation. Primary hepatic resection of the tumor was not possible in three other cases, and all received courses of chemotherapy without significant tumor shrinkage. One child underwent liver transplantation but died 4 months later of immunosuppression complications. The remaining three children died of disseminated malignancy. Histological verification of malignancy was difficult in three cases in which there was discrepancy between the rapid growth of the liver tumor and the microscopic features of benign hemangioendothelioma.