A 3.5-year-old child developed a tight oesophageal stricture following ingestion of caustic soda. At the end of the fourth anaesthetic for oesophageal dilatation, laryngospasm and difficulty in mask ventilation was followed by cyanosis, bradycardia, and cardiac arrest. Chest X ray showed a large pneumopericardium, which was immediately aspirated, but unfortunately resuscitation was unsuccessful. It was presumed that during attempted manual ventilation of the lungs in the presence of a closed glottis, air had been accidentally forced into the pericardium through a small tear in the fragile oesophagus.