Multidetector Computed Tomography (MDCT) technology plays an important role in the evaluation of injured patients. At our institution pelvic X-ray (PXR) is obtained routinely on trauma patients. Many also receive MDCT of the abdomen and pelvis for other indications. We hypothesized that there would be a substantial cost savings in adopting a policy of deferring PXR in a hemodynamically normal patient who will also proceed to MDCT for other indications. We retrospectively reviewed the charts of trauma patients from February 1, 2008 to February 1, 2009. We reviewed whether a PXR was done, the result, whether an MDCT was also done, and the presence or absence of pelvic fractures. We collected billing and cost data from various hospital sources. We identified 1,330 patients with PXR between February 1, 2008 and February 1, 2009. Of those patients, 810 (61%) had MDCT after PXR. Sixty-six patients (8.0%) had pelvic fractures; 39 were correctly identified on PXR (59% of fractures). Twenty-seven were detected only by MDCT (41% of fractures); all pelvic fractures were identified on MDCT. Seven hundred and forty-four patients (92% of patients with both PXR and MDCT) had negative PXR and negative MDCT. Using three methods of cost analysis, the estimated cost savings range is from $77,011 to $331,080. MDCT of the pelvis is more sensitive and more specific than PXR. In patients who are hemodynamically normal and asymptomatic, forgoing routine PXR could result in an estimated savings from $77,011 to $331,080, depending on the method used to calculate costs.