The patient was a 78-year-old man. An abdominal contrast-enhanced CT scan as a preoperative screening for bladder cancer showed a submucosal tumor at the gastric wall which was enhanced from the early phase to the venous phase with strong enhancement effect. Upper gastrointestinal endoscopy revealed a 25-mm submucosal tumor at the greater curvature of the upper body of the stomach. A biopsy showed cells which had oval-shaped nucleus and faintly eosinophilic cytoplasm had grown so as to surround small vessels. The tumor cells were α-SMA staining positive and then glomus tumor of the stomach was diagnosed. Although the number was small, mitotic figures were seen and a possibility of malignancy could not be ruled out. We thus decided to remove the tumor. Using intraoperative upper gastrointestinal endoscopy, we performed laparoscopic-assisted partial gastrectomy. The resected specimen was also diagnosed as gastric glomus tumor. There were no mitotic figures and malignant findings.Glomus tumor of the stomach is a relatively rare disease. The disease is benign in most cases, but few malignant cases have been reported. It is believed that the tumor over 5 cm in diameter has a possibility of distant metastasis. Since a gastric glomus tumor preoperatively diagnosed is rare, here we present this case.