Injury of diaphragm mainly occur in penetrating, crush and blunt injuries to the lower chest or upper abdomen, and it is most often secondary to automobile accidents. Diaphragmatic rupture is most frequent in blunt chest trauma and the rate is below 1% of them. Traumatic rupture of the diaphragm is responsible for the herniation of abdominal viscera. Physical finding and radiographic sign of diaphragmatic hernia is nonspecific and misreading. Therefore, the diagnosis of traumatic rupture of diaphragm may be difficult during the early period after the injury, especially when clinical features are dominated by associated injuries. Emergency surgical management is necessary when it is complicated with serious complication. We experienced the case of traumatic diaphragmatic hernia detected after the operation of femur fracture. The patient was injured by motor vehicle accident 6 days before the operation of the femur fracture. There was no specific symptom and sign and the manifestation of the diaphragmatic hernia. in radiographic studies until operation of the femur fracture was done. Diaphragmatic hernia was confirmed by chest X-ray and arterial blood gas analysis after operation of the femur fracture. The repair of the diaphragmatic hernia was directly performed after the diagnosis. The prognosis was favorable, and she was discharged to ward from intensive care unit after 1 day of operation. We must consider the possibility of traumatic diaphragmatic hernia in the patient who have the history of blunt chest or abdominal trauma.