Gastrointestinal leiomyomas are commonly found in the stomach, and but 3% of them arises from the colon. Colonic leiomyomas are often found incidentally during colonoscopic examination. Most of patients with colonic leiomyoma are asymptomatic, but patients with large size leiomyoma occasionally have abdominal mass, hemorrhage, intestinal obstruction or perforation. Pedunculated leiomyomatous polyp is rare. Leiomyomatous polyps are occasionally misjudged as adenomatous polyps by endoscopist. We report a case of pedunculated leiomyomatous colonic polyp in 65 year-old female patient. She has complained of intermittent hematochezia and lower abdominal discomfort for 5 months. During colonoscopy, an 1 cm sized long pedunculated polyp at the splenic flexure was detected. It was removed by colonoscopic snare polypectomy. Leiomyomatous polyp was confirmed by microscopic and immunohistochemical findings.