Adenomyomas of the stomach are rare tumors characterised by duct/gland-like structures embedded within a smooth muscle stroma. A 5-year-old female patient was admitted to the department of Pediatrics, Ewha Womans University MokDong Hospital with the history of severe epigastric pain and vomiting for 1 day. Esophagogastroduodenoscopy showed bridging fold with central dimpling on posterior wall of prepyloric antrum. Endoscopic biopsy was nondiagnostic. The patient complained epigastric pain continuously and underwent wedge resection. Pathologic examination showed an adenomyoma of the prepyloric antrum. After wedge resection, the patient did not complain epigastric pain during the postoperative follow-up. We report an unusual case of an adenomyoma of stomach.