A 60-year-old woman who admitted to our institute due to general malaise for 1 year was found to have a huge hepatic mass at ultrasound and CT. The hepatic tumor was histologically confirmed to be undifferentiated embryonal sarcoma by means of percutaneous needle biopsy under ultrasound guidance. Though this malignant hepatic tumor usually occurs in children and young adults, we report a case of undifferentiated embryonal sarcoma that occurred in an old woman.