Gastroduodenal intussusception, an invagination of a part of the gastric wall through the pyloric canal into the duodenum is a rare condition. Gastroduodenal intussusception is caused by a mobile usually benign gastric tumor. However, gastroduodenal intussusception by gastric submucosal hemangiomatosis is not documented. We have managed a case of gastric submucosal tumor leading to gastroduodenal intussusception in 2 years and 10 months old boy. The tumor was $10{ imes}5{ imes}3cm$ in size in posterior wall of gastric antrum. Laparotomy, manual reduction of the intussusception, and wedge resection of posterior gastric wall including the tumor were performed. Pathologic diagnosis was a submucosal hemangiomatosis.