We describe a rare case of ulcerative colitis (UC) with lymphoid follicular proctitis (LFP) extending discontinuously from the rectum to the ascending colon. The patient was a 42-year-old female presenting with a positive fecal occult blood test. Colonoscopy revealed erosions and disappearance of vascular patterns in the ascending colon and lower rectum, together with circumferential, uniform, granular lesions in the lower rectum. Histological examinations of the rectal biopsy specimens revealed lymphoid follicles, hyperplasia, and infiltration of chronic inflammatory cells. We suspected rectal and segmental UC with LFP. Initially, the patient was managed conservatively because of the lack of symptoms; however, on developing mucoid stools and haematochezia, mesalazine administration was started. Her symptoms and endoscopic findings resolved completely. LFP is closely associated with UC. Therefore, while diagnosing and managing LFP, it is necessary to ascertain or rule out potential complications.