Purpose: National Emergency X-Radiography Utilization Study (NEXUS) criteria and the Canadian Cervical Spine rule (CCR) are commonly used in cervical trauma patients to determine whether a plain cervical X-ray should be performed. However, plain cervical X-rays are so inaccurate that cervical spine computed tomography (CT) is often considered as a screening test. We studied the usefulness of the NEXUS criteria and the CCR for determining the need for a CT evaluation in the emergency department (ED). Methods: This prospective observational study was conducted from January 2007 to March 2008. Plain X-ray and CT scans of the cervical spine were performed on blunt trauma patients with neck pain. The relevancy of CT was examined using the NEXUS criteria and the CCR. Sensitivity, specificity, positive predicted value, and negative predicted value analyses were performed to diagnose the cervical spine injury. Results: During the study period, 284 patients were enrolled in this study. The sensitivity, specificity, positive predicted value, and negative predicted value of the NEXUS criteria were 87.5%, 1.1%, 5.0%, and 60.0% respectively, while those of the CCR were 87.5%, 8.2%, 5.3%, and 91.6%. There were two missed fracture cases when the NEXUS criteria and the CCR were applied independently, however, no cases were missed when both were applied. Conclusion: This study suggests the NEXUS and the CCR in combination can be used as a guide to CT evaluation for cervical spine injury in the ED.