Inflammatory fibroid polyp (IFP) is a rare benign fibroproliferative disease that arises from the submucosal layer of the gastrointestinal tract. Surgical resection has been performed in most cases and the application of endoscopic resection is rare. Endoscopic submucosal dissection (ESD), which was recently introduced, enables en-bloc resection of a tumor regardless of the tumor size and location. Since IFP is benign, ESD can be very useful for both the diagnosis and treatment of a large-sized IFP. A 45-year-old woman was referred for the management of a gastric mass. Esophagogastroduodenoscopy showed a round submucosal mass with a central bulging at the gastric body. Endoscopic ultrasonography showed a 3.5x3.0 cm-sized hypoechoic mass in the third layer of the stomach. The tumor was removed by ESD with using a hook knife for complete en-bloc resection. The pathologic finding was compatible with the diagnosis of IFP. We report here on a case of IFP that presented as a gastric submucosal tumor and it was treated by the ESD method.