A 57-year-old female was found a 12 mm × 10 mm submucosal lesion in the rectum with a smooth mucosa and telangiectasia The lesion was considered as a neuroendocrine tumor, and removed by endoscopic submucosal dissection (ESD) It was finally diagnosed with mucosa-associated lymphoid tissue (MALT) lymphoma with negative margin by pathological examination and histopathological test. MALT lymphoma in the rectum is rare and difficult to diagnose without histopathological test. In this case, the characteristic of this case is telangiectasia on the surface of lesion. Therefore, our findings suggested small lesion in rectum but big in impact.