A 43-year-old man with a 23-year history of remission for Crohn's disease was admitted to our hospital because of stomachache and anal pain. Computed tomography showed fistula formation between the ileum and the sigmoid colon. Colonoscopy revealed two elevated tumors in the rectosigmoid and lower rectum. Synchronous double colitic cancer with Crohn's disease was diagnosed. We performed an abdominoperineal resection and an ileocecal resection. Histopathological examination revealed a rectosigmoid tumor invading the ileum and bladder with intestinal mesenteric and lateral lymph node metastasis, Stage Ⅳ. Postoperatively, the patient received adjuvant chemotherapy with mFOLFOX6 plus bevacizumab. Nine months after the operation, he was diagnosed with right pleural dissemination and effusion. He died after 13 months. Synchronous double colitic cancer in Crohn's disease is very rare and is often advanced at the time of diagnosis. These findings suggest that patients with Crohn's disease need periodic surveillance.