Congenital para-oesophageal hiatal hernia (PEHH) is a rare problem in infancy, however, it constitutes a clinical entity that mandates surgical repair once the diagnosis is made. In the paediatric age group, acquired PEHH has been described as a major complication in a number of patients who were treated surgically for gastro-oesophageal reflux (GER) by Nissen fundoplication. PEHH is a frequently encountered condition in elderly patients; it accounts for 5% of diaphragmatic hiatal hernias. In both paediatric and adult patients PEHH, whether congenital or acquired in origin, is usually associated with potentially lethal complications such as gastric volvulus, incarceration, and perforation. In clinical practice true PEHH is extremely rare. The term has been expanded to include large gastric hiatal hernias where most of the stomach and the gastro-oesophageal junction are in the chest. Six infants with congenital PEHH are presented, together with an attempt to understand its possible aetiology and a review of its current surgical management.