A 62-year-old male who had had the left femoral neck fracture due to a traffic accident 1 year earlier was admitted to our hospital because of abdominal pain. He was diagnosed with a left traumatic diaphragmatic hernia due to the previous traffic accident; his condition was also complicated by shock because the mediastinum was compressed by his severely dilated stomach. We performed an emergent operation. A thoracotomy revealed a large defect, about 5 cm in size, at the central tendon of the left diaphragm and a severely dilated stomach in the left thoracic cavity. The ruptured diaphragm was closed directly after reduction of the stomach.