Our study objective was to determine whether simple clinical criteria can be used to safely reduce the number of patients who require cranial computed tomography (CT) scan after sustaining minor head trauma. Awake patients (Glascow Coma Scale = 15) who presented to the emergency department with acute head injury associated with a loss of consciousness were evaluated for clinical predictors of head injury prior to CT scan. The studied risk factors included severe headache, nausea, vomiting, and depressed skull fracture on physical examination. Patients with no risk factors present were compared with patients with one or more risk factors with respect to abnormal CT rate and rate of operative intervention for head injury. Of the 2143 patients entered into the study, 1302 (61%) had no risk factor for head injury, whereas 841 (39%) had one or more risk factors present. A total of 138 (6.4%) of those studied had an abnormal CT scan. This number included 3.7% of those patients with no risk factors vs. 11% in patients with one or more risk factors. The CT scan abnormalities in the no-risk-factor group were not clinically significant. All 5 patients who required operative intervention had at least one of the risk factors present. The use of four simple clinical criteria in minor head trauma patients would allow a 61% reduction in the number of head CT scans performed and still identify all patients who require neurosurgical intervention and the majority of patients with an abnormal CT scan. This method could lead to a large savings in patient charges nationwide. Further studies may be helpful in confirming these findings.