In colon, smooth muscle tumors are extremely rare and represent only 3% of digestive tract leiomyomas. A 51-year- old women was admitted with complaints of epigastric pain and weight loss. Colonoscopy revealed a large pedunculated polyp covered with almost normal mucosa in the proximal transverse colon. After clipping of the stalk, we performed polypectomy successfully by colonoscopic snare electrocoagualtion. We report a case of endoscopic removal of colonic pedunculated leiomyoma with a review of literature.