On admission. Preliminary examination showed that he had a fractured right clavicle, fractured pelvis and injuries to the chest wall anteriorly. Surgical emphysema was palpated over the front of his chest and an immediate chest X-ray showed evidence of pulmonary contusion. About 4 hr later another chest X-ray ( Fig. 1) was taken because of increasing dyspnoea. This showed a pneumothorax on the left side and a gas shadow above the diaphragm.The next day further views of the chest (Figs. 2 and 3) and a gastrografin swallow were performed. The impression gained was that the bowel, probably colon, was situated in the anterior mediastinum, possibly in the pericardium. On this day the patient complained of increasing upper abdominal pain, and an electrocardiogram showed a sinus tachycardia of 140/min. Laparotomy was performed through a midline epigastric incision and a dilated loop of transverse colon was found lying in front of and above the liver. This was withdrawn easily and revealed a large transverse tear in the central tendon of the diaphragm leading directly into the pericardial cavity. The tear was between 4 and 5 in. long and the margins, which were ragged, were stretched apart. There was no hernial sac. Access from below was inadequate to allow a satisfactory repair so a left thoracotomy was performed through the fifth intercostal space and the peri-*Present address: Liandough Hospital, Cardiff.cardial sac was opened. With retraction of the lower border of the heart this gave good ex-