Tumors in the retrorectal area are rare. Surgical approaches to retrorectal tumors include posterior, anterior, or combined approaches. We have encountered a case of a 56- year-old woman with a retrorectal tumor. She had a solid tumor, 3 cm in size, in the posterior midline rectum 7 cm above the anal verge. The tumor was successfully resected by using a posterior (transsacral) approach with a partial sacrectomy and was diagnosed as being a neurofibroma. There were no postoperative complications.