Fifteen patients with chronic postoperative bilious vomiting were treated by repair of hiatus hernia with satisfactory relief of symptoms. Two patients were known to have had hiatus hernia prior to the first gastric operation; nine patients were believed to have had hiatus hernia prior to the first gastric operation, but this fact is not certain; and in four patients it was suspected that transabdominal vagotomy may have had an iatrogenic role in the development of gastroesophageal incompetence. As a result of this retrospective study it was concluded that undiscovered sliding esophageal hiatus hernia is the cause of bilious vomiting in many patients heretofore thought to have the "afferent-loop syndrome."