['Patients with MHI and a positive head computed tomography (CT) scan frequently have a routine repeat head CT (RRHCT) to identify possible evolution of the head injury requiring intervention. RRHCT is ordered based on the premise that significant injury progression may take place in the absence of clinical deterioration.', 'In a Level I urban trauma center with a policy of RRHCT, we reviewed the records of 692 consecutive trauma patients with Glasgow Coma Scale scores of 13-15 and a head CT (October 2004 through October 2005). The need for medical or surgical neurologic intervention after RRHCT was recorded. Patients with a worse and unchanged RRHCT were compared, and independent predictors of a worse RRHCT were identified by stepwise logistic regression.', 'There were 179 patients with MHI and RRHCT ordered. Of them, 37 (21%) showed signs of injury evolution on RRHCT and 7 (4%) required intervention. All 7 had clinical deterioration preceding RRHCT. In no patient without clinical deterioration did RRHCT prompt a change in management. A Glasgow Coma Scale score less than 15 (13 or 14), age higher than 65 years, multiple traumatic lesions found on first head CT, and interval shorter than 90 minutes from arrival to first head CT predicted independently a worse RRHCT.'] Is routine repeat head CT for minimal head injury unnecessary?