Injuries of the diaphragm in 86 patients occurring over a 10-year period were retrospectively reviewed. Blunt trauma victims experienced injury on the right and left with nearly equal frequency, representing a strikingly different experience from those reporting before. 1970 when left-sided injuries predominated.Patients' complaints and physical findings were not reliable indicators of diaphragm injury, but were usually manifestations of associated injury. Ninety-five per cent of our acute victims had other injuries. Routine chest X-rays were the most reliable diagnostic tools, yet these were normal in 1/4 of the patients. Diagnosis depends on high index of suspicion before operation and careful inspection of the diaphragm at operation. Initial thoractomy required subsequent laparotomy to complete management in seven of 15, whereas laparotomy required supplemental thoractomy only once in 65 instances. The superior operative approach, therefore, for either right or left diaphragmatic injury is initial laparotomy.