We report a rare case of endoscopic removal of colonic pedunculated leiomyoma with an aid of endoscopic ultrasonography (EUS). A 46-year-old man was admitted to our hospital with complaints of lower abdominal pain and alternating constipation and diarrhea. Colonoscopy revealed a small pedunculated polyp in the transverse colon covered with almost normal mucosa. EUS showed a hypoechoic solid tumor with clear margins and smooth contour in the second to third layer. We considered this lesion as a submucosal tumor of the colon with no continuity to the muscularis propria. We performed endoscopic removal of this tumor successfully, and histological diagnosis was a leiomyoma. Endoscopic removal of colonic pedunculated leiomyoma is rare. Moreover, in our case, EUS showed typical findings of colonic leiomyoma and was useful to assess the location of the submucosal tumor. We describe herein our experience and discuss similar cases reported in the English literature.