A case of ependymoma originated in pelvic cavity is reported. Metastasis to regional lymph nodes and abdominal cavity developed. This tumor is thought to arise from heterotopic ependymal rests. The patient was 32 year old woman. A 10.0x7.0x7.0 cm sized mass was located between the uterus and rectum, which was attached to the rectal wall. It was a well circumscribed tumor with massive hemorrhage and necrosis. Histologically, tumor showed variegated appearance. Plump oval or round cells were arranged oval of elongated cells with fibrillary cytoplasmic process. Occasionally perivascular pseudorosette and ependymal rosette were seen. Immunohistochemical staining for GFAP showed intense positivity. Ultrastructural examination showed intracytoplasmic microfilaments, cilia, microvilli, and blepharoplasts.