OBJECTIVE. The purpose of our study was to compare the cost-effectiveness of bilateral oblique radiography with that of CT for excluding C7-T1 injury in trauma patients. MATERIALS AND METHODS. Using a historical cohort model, we retrospectively studied two distinct groups of trauma patients. In the first group, which included 196 patients, CT was performed to show C7-T1 anatomy when this region was not adequately revealed on initial three-view cervical spine radiography. In the second group, which included 129 patients, routine three-view radiography was complemented by bilateral oblique views. If these five views failed to adequately reveal C7-T1 anatomy, CT was then performed to show the cervicothoracic junction. Using Medicare reimbursement data, we then compared the cost-effectiveness of CT with that of oblique radiography in terms of cost per cervical spine imaged completely to the level of C7-T1. RESULTS. In the first group, 50 (26%) of 196 patients underwent CT when C7-T1 anatomy was not adequately revealed on routine three-view cervical spine radiography. In the second group, only 17 (13%) of the 129 patients required CT when five-view radiography failed to adequately reveal C7-T1 anatomy. This difference was statistically significant (p <.01). The cost per completely imaged cervical spine was $92.00 when bilateral oblique radiographs were routinely obtained, compared with $116.28 per completely imaged cervical spine when these views were not obtained. CONCLUSION. Because bilateral oblique radiography appears to be cost-effective for the exclusion of cervical spine injuries, we suggest that it be performed routinely.