A 41-year-old woman was diagnosed with ulcerative colitis (UC) in 1988 and was receiving maintenance therapy at a local clinic. In 2016, her symptoms deteriorated, and she was referred to our hospital to start steroid treatment. Lower gastrointestinal endoscopy showed a circumferential Type 3 tumor in the upper rectum. UC-related rectal cancer (colitic cancer) was diagnosed, and laparoscopic total colectomy, ileoanal anastomosis, and ileostomy formation were performed. The histopathological diagnosis was rectal signet-ring cell carcinoma, pT3(SS)N2bM1a(LYM), pStage IVa. Postoperatively, 12 courses of mFOLFOX6 were administered, but computed tomography 1 year postoperatively showed enlargement of the left ovary and ileal mesenteric lymph nodes. Laparoscopic bilateral adnexectomy and ileoanal resection were performed, and bilateral ovarian and ileal mesenteric lymph node metastases of rectal signetring cell carcinoma were diagnosed. Postoperative chemotherapy was administered, but peritoneal dissemination recurred 16 months after the second surgery, and the patient died of the underlying disease 39 months after the initial operation. Key words:colitic cancer,signet-ring cell carcinoma,ovarian metastasis