Study objective: To determine the clinical value of routine computed tomography (CT) of the head in patients with normal mental status after minor head trauma. Methods: We carried out a prospective study of a consecutive series of patients of all ages who presented to our urban university Level I trauma center emergency department with a Glasgow Coma Scale score of 15 and underwent CT of the head after loss of consciousness (LOC) or amnesia to event. A data form was filled out for each patient before CT. Patients with abnormal CT results were followed to discharge. We analyzed data with the χ² and Student t tests. Results: Of 1,382 patients, traumatic intracranial abnormality was identified on CT of the head in 84 (6.1%). Three patients in this group (.2%) required surgery. The subgroup of patients with history of LOC/amnesia but no symptoms or signs of a depressed skull fracture had a rate of abnormal CT findings of only 3% (24 of 789), and no patient in this group required medical or surgical intervention. Nausea and vomiting and signs of head trauma were significantly more common in the group with abnormal CT findings. Conclusion: Routine CT of the head in patients with history of LOC/amnesia but no symptoms or signs of depressed skull fracture has minimal clinical value and is not warranted. Patients with symptoms of head injury or apparent depressed skull fracture should undergo head CT because a small number will require surgery. [Miller EC, Derlet RW, Kinser D: Minor head trauma: Is computed tomography always necessary? Ann Emerg Med March 1996; 27:290-294.]