A 65-year-old woman was admitted to the hospital because of anal discomfort. An elastic soft mass was palpable with the finger tip on the posterior wall of the rectum. CT scan showed a cystic tumor, which measured 8cm in diameter at the presacral space. The border between the tumor and the rectum was unclear. Barium menema examination demonstrated a forward displacement of the posterior wall of the rectum. Fine needle aspiration cytology revealed squamous cell carcinoma. Rectal amputation was performed under a preoperative diagnosis of presacral malignant tumor. The resected material revealed a cystic tumor, 7×7×3.5cm in size. In the section, no bone, caetilage and hair were found. Histopathologically, the most part of cyst wall was moderately differentiated squamous cell carcinoma, a part of this was squamous epitherium without any skin appendages. Therefore the diagnosis was squamous cell carcinoma arising from presacral epidermoid cyst. A few reports of presacral epidermoid cysts have been seen, but so far we have never seen the case of squamous cell carcinoma arising from presacral epidermoid cyst.