Traumatic dislocation of the lumbar verteba on the sacrum is a very rare injury Which usually results from major trauma. In a review of the literature, only 20 cases have been documented. We experienced a case of traumatic lumbosacral dislocation in a nineteen-year-old man with left fourth transverse process fracture, who was treated by open reduction and interspinous wiring with lumbosacral fusion. This case demonstrates this unusual lesion both radiographically and by the use of computerized axial tomography (CT).