Endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) is performed to obtain specimens for pathological analysis. For this procedure, 19-gauge (19G), 22-guage (22G), and 25-guage (25G) needles are available. The needles are classified into aspiration type and biopsy type. A 56-year-old woman underwent upper gastrointestinal endoscopy that showed a 38-mm-diameter submucosal tumor. The elevated lesion was diagnosed as a submucosal tumor of the stomach. Contrast-enhanced computed tomography showed a low-density area on the luminal surface of the gastric wall, which was covered with a thin layer of gastric mucosa. EUS showed a hypoechoic lesion in the submucosal layer. Color Doppler image showed a pulsating vascular signal extending into the center of the hypoechoic lesion from the periphery. EUS-FNA was performed with a 25G biopsy needle. The specimen tissue consisted of spindle-shaped cells. The cells were positive for CD117 and CD34. The submucosal tumor was diagnosed as a gastrointestinal stromal tumor.