A 69-year-old woman was referred to our hospital with symptom of tumor prolapsed through anus. A yellowish and elastic soft mass protruding through the anal verge was seen in physical examination, however it was manually reducible. Colonoscopy revealed a large tumor with a diameter of 100 mm located in the sigmoid colon. According to CT and MRI, the tumor was diagnosed as a pedunculated lipoma of the sigmoid colon. Because the tumor was too large to be strangled by snare and the feeding vessel was firm, we selected endoscopic submucosal dissection (ESD) instead of polypectomy. Final histopathological diagnosis showed the tumor as submucosal lipoma. Cases of endoscopic removal for symptomatic colonic lipoma has been increasing. However, there are no cases reported that lipoma, prolapsed from anus, was treated with ESD in Japan.