Background: Routine performance of thoracolumbar (TL) spinal radiology in patients with blunt trauma is controversial. Patients and methods: To establish indications for radiologic screening of the TL spine, a retrospective review of 344 patients who had radiologic evaluation of the spine was performed. Results: Forty-seven patients had abnormalities detected on radiologic evaluation. One hundred eighty-six patients had at least one clinical finding suggestive of injury. Thirty-two had abnormal radiographs. Thirteen of these abnormalities represented old or minor fractures and were not treated. Nineteen patients had injuries requiring treatment. Two patients were treated with activity restriction, 12 with a back brace, 4 with operative fixation, and 1 patient died prior to operation. Of the 129 patients who were awake, alert, and without clinical evidence of injury, 10 had abnormal radiologic studies. Three patients had old fractures, 4 had transverse process fractures, and 3 had spondylolisthesis. None of these patients required treatment. Twenty-nine patients had equivocal clinical examinations primarily due to altered levels of consciousness. Five patients had abnormal radiologic studies, 3 of whom required treatment. Three factors associated with the occurrence of TL spine injury were identified: an injury Severity Score ≥15, a positive clinical examination, and a fall of ≥10 feet. Conclusions: These data suggest that patients who are awake, alert, and with no clinical evidence of injury do not require radiologic study of the TL spine. Patients with equivocal or positive clinical findings or with altered levels of consciousness should have complete TL spine evaluation.