Traumatic brain injury (TBI) is a leading cause of childhood death and disability worldwide. In the United States, childhood head trauma results in approximately 3,000 deaths, 50,000 hospitalizations, and 650,000 emergency department (ED) visits annually. Children presenting to the ED with seemingly minor head trauma account for approximately one-half of children with documented TBIs. Despite the frequency and importance of childhood minor head trauma, there exists no highly accurate, reliable and validated clinical scoring system or prediction rule for assessing risk of TBI among those with minor head trauma. At the same time, use of CT scanning in these children in recent years has increased substantially. The major benefit of CT scanning is early identification (and treatment) of TBIs that might otherwise be missed and result in increased risk of morbidity and mortality. Unnecessary CT imaging, however, exposes the child needlessly to the risk of radiation-induced malignancies. What constitutes appropriate criteria for obtaining CT scans in children after minor blunt head trauma remains controversial. Current evidence to guide clinicians in this regard is limited; however, large studies performed in multi-center research networks have recently been conducted. These studies should provide the foundation of evidence to guide CT decisions by clinicians, help identify TBIs in a timely fashion, and reduce unnecessary radiation exposure.