A case of diaphragmatic paraesophageal hernia complicated by omentum and gastric incarceration is reported. The pure paraesophageal hiatal hernia is a rare entity. The symptoms and complications are caused by the anatomic defect and not by gastroesophageal incompetence. Chronic, recurrent, asymptomatic blood-loss anemia is the most common complication. Gastric volvulus is frequent in which the stomach herniated in a huge parietal peritoneal sac in the chest behind the heart. Volvulus may be a chronic recurrent problem or an acute life threatening complication. The diagnosis depends on the patient's symptoms and the demonstration by radiography, but difficulties may occur in the presence of complications, as in the case reported. Surgical repair is indicated, with sac excision and hiatusplasty.