Malignant peripheral nerve sheath tumor (MPNST) of the liver is rare. Most cases of MPNST are accompanied by neurofibromatosis 1 (NF-1, von Recklinghausen's disease). We herein report an autopsy case of MPNST without NF-1 and review the pertinent literature. The tumor occupied the entire lobe of the liver, and was 18 cm in maximum diameter. The tumor revealed necrosis and cystic changes with hemorrhage and it had also metastasized to the peritoneum. Microscopically, the tumor was composed of pleomorphic spindle cells with hyperchromatic nuclei and mitogenic figures. The spindle cells stained positive for both S-100 and vimentin antibodies.