Superior mediastinal widening on chest radiograph in patients with trauma has been considered the hallmark of mediastinal hemorrhage. The usual causes of superior mediastinal widening are hematoma, aortic rupture, and rupture of the esophagus or tracheobronchial tree. Very rarely, a cause of superior mediastinal widening is leakage of the cerebrospinal fluid. This report descrbes a case of superior mediastinal widening from traumatic cerebrospinal fluid leakage with spinal fracture.