Background: Thoracolumbar fracture (TLF) is one of the common problems associated with trauma. This study evaluated the diagnostic value of chest and abdominopelvic computed tomography (CT) in detecting TLFs among patients with blunt trauma. Methods: This prospective diagnostic assessment study was conducted during 2016-2017. Participants were 256 patients above 18 years with blunt multiple trauma who had undergone chest and abdominopelvic CT at their admission to the emergency department and were subjected to thoracolumbar CT (TL CT) for the further assessment of TLFs. The sensitivity, specificity, and positive and negative predictive values of chest and abdominopelvic CT were calculated based on TL CT findings. Results: The total sensitivity, specificity, and positive and negative predictive values of chest and abdominopelvic CT in detecting TLFs were 89. 55%, 100%, 100%, and 89. 71%, respectively. These values were, respectively, 95. 56%, 100%, 100%, and 98. 39% in detecting transverse process fractures; 50%, 100%, 100%, and 91. 04% in detecting vertebral body fractures; and 80%, 100%, 100%, and 65. 24% in detecting vertebral body and posterior element fractures. Chest and abdominopelvic CT sensitivity and specificity were, respectively, 97. 5% and 100% among patients younger than 40 years and 77. 4% and 100% among patients older than 40 years. There was a significant agreement between chest and abdominopelvic CT and TL CT findings (kappa coefficient = 0. 896; P < 0. 001). Conclusion: Chest and abdominopelvic CT has acceptable sensitivity and specificity in detecting TLFs. However, due to low sensitivity and specificity in detecting vertebral body fractures without posterior element involvement and clinical importance of these fractures, image reformatting is suggested. Of course, TL CT can be used in case of suspicious fractures or older patients.