The esophageal hiatal hernia is a rare disease entity in children, Especially, the paraesophageal hiatal hernia is an extremely rare. We had experienced a paraesophageal hiatal hernia in 6 month old male baby. He had postprandial vomiting for 4 months. The chest P-A and right lateral X-ray films were shown a round homogenous density in posterior mediastinum. On laparotomy, we couldn`t see the stomach in operative field. We reduced the stomach through the widened esophageal hiatus and repaired hiatal opening. His operative course was uneventful and discharged on the 9th postoperative day.[KTCS 1978;3:355-358]