Gastric subepithelial masses might harbour gastrointestinal stromal tumors, which should get resected because of their malignant potential. To minimize the associated surgical trauma endoscopic endoluminal resection is favorable. Therefore in the current study endoscopic resection of gastric subepithelial masses is investigated. Since there is a certain risk of perforation due to the procedure, perforations get closed by placement of endoscopic clips (over-the-scope-clip [OTSC] clips).