Data were prospectively collected on the signs, symptoms and physical findings in 2225 patients who underwent computed tomography (CT) of the head in a tertiary care teaching hospital. These data were correlated with the results of CT in an attempt to identify evidence of inappropriate utilization of diagnostic cranial CT. If only those patients had been examined whose presenting complaints were statistically more often seen in patients with abnormal CT studies than in those with normal CT studies, 26% of all examinations would have been eliminated, but 18% of all abnormal patients would have been missed. If only those patients who were thought by their physicians to have a high likelihood of intracranial disease or to be diagnostic dilemmas had been examined, 34% of all examinations and 26% of all abnormal CT studies would have been eliminated. In the setting studied here, there is no evidence for inappropriate utilization of cranial CT for diagnostic purposes.