Objective:To evaluate the clinical efficacy and safety of endoscopic submucosal dissection (ESD) for treatment of duodenal lesions.Methods:A retrospective analysis was performed on the data of 45 patients with 46 duodenal lesions who underwent ESD at the Second Xiangya Hospital of Central South University from January 2011 to May 2019. The lesion features, en bloc resection rate, complete resection rate, complications, postoperative pathology and recurrence were assessed.Results:Among the 45 patients, 20 were males and 25 were females, with age of 52.0±11.8 years. Of the 46 lesions, 31 (67.4%) were located in the duodenal bulb, 12 (26.1%) in the descending part, and 3 (6.5%) at the junction of bulb and descending part. The diameter of the lesions was 2.4±1.9 cm. There were 14 (30.4%) lesions originated from mucosal layer, 29 (63.1%) from submucosal layer, and 3 (6.5%) from muscularis propria.Postoperative pathology showed 11 (23.9%) cases of Brunner gland tumors, 9 (19.6%) neuroendocrine tumors, 5 (10.9%) ectopic pancreas, 5 (10.9%) lipomas, and 16 (34.8%) other pathological patterns. All 45 patients with 46 lesions underwent ESD successfully, and the en bloc resection rate was 100.0% (46/46), complete resection rate was 91.3% (42/46). Intraoperative bleeding occurred in 1 case (2.2%), which was successfully treated by endoscopy. One (2.2%) delayed perforation occurred and was treated by surgical intervention. Electrocoagulation syndrome occurred in 1 case (2.2%), which was relieved after conservative medical therapy. Two cases received further surgery after ESD. The mean hospital stay was 6.2 days (ranged 2-21 days) and no death occurred. Forty-one cases were followed up for 1-78 months, with mean time of 30 months. During the follow-up period, local recurrence occurred in 1 patient (2.4%).Conclusion:ESD is an effective and safe treatment for duodenal lesions and has a good clinical practical value.