Traumatic rupture of the diaphragm may be caused by either penetrating or blunt trauma. The diagnosis is often delayed because of attention to other serious injuries or lack of specific clinical and radiographic signs. In cases of penetrating peridiaphragmatic trauma, the possibility of a diaphragmatic laceration may not be considered, or the plain film findings may be extremely subtle or absent . We report a case of delayed presentation of traumatic diaphragmatic hernia demonstrated by real-time sonography . To our knowledge, this is the first reported case in which sonography provided a definitive diagnosis and prompted immediate surgical repair.