An 86-year-old patient was transferred to our institution with acute respiratory distress. A tension pneumothorax was suspected, but needle decompression was unsuccessful. Instead of the suspected pneumothorax, the chest radiograph revealed a large 'tension gastrothorax'. In a matter of seconds, the insertion of a nasogastric tube resulted in drastic improvement of the critical clinical state. Acute tension gastrothorax is a rare, but classic, complication of paraoesophageal hernias. Its clinical presentation can be dramatic and rapidly lethal, immediate action is therefore warranted. Nasograstric tube insertion is a life saving procedure to be undertaken without delay. However, tension gastrothorax is a rare entity. Therefore, if tension pneumothorax is suspected, needle decompression should not be delayed.