Small (<2 cm) or incidentally found gastrointestinal submucosal tumors pose challenges to gastroenterologists due to the potential malignancy of tumors and current suboptimal diagnostic methods. On the basis of the development of endoscopic submucosal dissection, recent technical advances, including endoscopic submucosal excavation, submucosal tunneling and endoscopic resection, and endoscopic full-thickness resection, have been able to resect submucosal tumors in the muscularis propria. These techniques provide definitive histologic diagnosis as well as a minimally invasive therapeutic approach to such tumors. Current studies, despite with promising results, are limited to small, retrospective studies, focusing on introducing new methods and varied in technical details. This review provides a thorough discussion of technical details of each endoscopic method, and compares different methods in terms of tumor sites, to ensure safety and optimize treatment outcomes.