We report a case of colonic metastasis from ovarian cancer presented as an intraluminal fungating mass mimicking primary colon cancer 8 years after surgery for ovarian cancer. A 70-year-old woman presented with constipation. She had undergone an extended total abdominal hysterectomy with bilateral salpingo-oophorectomy for an ovarian papillary serous cystadenocarcinoma 8 years earlier. Colonoscopy showed a large fungating mass 10 cm from the anal verge that was suspected to be colorectal cancer. A computed tomography scan showed a bulky intraluminal fungating mass in the rectosigmoid junction. After a lower anterior resection and a pathologic diagnosis, a diagnosis of a papillary serous adenocarcinoma due to metastasis from an ovarian tumor was made for this patient.