Objective To evaluate the efficacy and safety of modified endoscopic submucosal dissection (ESD) utilizing a mushroom extraction method for gastric ectopic pancreas. Methods From June 1, 2009 to June 30, 2023, data of 190 patients (191 lesions) with pathologically confirmed heterotopic pancreas who underwent resection using modified ESD with mushroom extraction method in Shandong Second Provincial General Hospital (n=99) and the 960th Hospital of the PLA Joint Logistics Support Force (n=91) were retrospectively analyzed. The clinical characteristics and endoscopic and endoscopic ultrasonography (EUS) features were summarized and the treatment effects of the modified ESD was evaluated. The complications and follow-up recurrence were analyzed. Results Preoperative EUS showed that most lesions originated from the submucosa and often involved multiple layers, invading the muscularis propria in 12 cases. A total of 191 gastric lesions included 174 in the gastric antrum, 2 pyloric canal, 6 gastric body, 7 gastric angle and 2 gastric fundus. The long diameter of the lesions ranged from 0.5-4.0 cm. All patients underwent modified ESD with the mushroom extraction method, and the complete removal rate of specimens was 99.5% (190/191). The operation time was 0.5-2.5 h. There were 10 cases of intraoperative perforation; 1 case of postoperative delayed perforation, 1 case of delayed hemorrhage, and 3 cases of short-term fever. Patients were followed up for 3-5 years after the operation, and no recurrence or metastasis was found. Conclusion The modified ESD technique incorporating mushroom extraction proves to be a safe and effective approach for the complete removal of gastric ectopic pancreas, minimizing the risk of recurrence and residual pancreatic tissue.