BACKGROUND One treatment for colon endoluminal tumors is endoscopic resection, i.e., endoscopic mucosal resection (EMR). In this report we describe a case of an endoluminal tumor resected safely and completely by combined endoscopic and laparoscopic surgery (CELS). CASE REPORT A 70-year-old female was admitted to our hospital for cholelithiasis, and we planned a cholecystectomy. She had a surgical history for endometrial cancer, and she was taking amlodipine 2.5 mg/day for hypertension. A preoperative colonoscopy for screening revealed an 18-mm endoluminal tumor in the sigmoid colon. We tried to resect it by EMR, but flexion of the colon, which was considered to be due to adhesion from the former surgical treatment, was severe, so it was difficult to resect the endoluminal tumor by endoscopy. We conducted laparoscopic cholecystectomy and sigmoid colon mobilization. Sigmoid colon flexion was released, enabling us to conduct EMR to the endoluminal tumor. No intraoperative or postoperative complications were observed. CONCLUSIONS CELS can make an endoluminal tumor resectable by EMR without colon resection, and performing simultaneous CELS and laparoscopic cholecystectomy is less invasive.