The objective of this study is to characterize changes in computed tomography (CT) utilization in the pediatric emergency department (ED) over a 6-year period. CT scans ordered on pediatric (ages 0 to 17 years) ED patients from July 2000 to July 2006 were analyzed in five groups: head, cervical spine, chest, abdomen, and miscellaneous. Pediatric ED patient volume and triage acuity scores were determined. There were 6,073 CT scans performed on 4,138 pediatric patients in the ED during the study period. During this same period, 78,932 pediatric patients were evaluated in the ED. From 2000 to 2006, pediatric ED patient volume increased by 2%, while triage acuity remained stable. During this same period, head CT increased by 23%, cervical spine CT by 366%, chest CT by 435%, abdominal CT by 49%, and miscellaneous CT by 96%. Increases in CT utilization were most pronounced in adolescents ages 13 to 17 years. Increases in CT utilization in this age group met or exceeded increases seen in the adult population. In children less than 13 years of age, increases were substantially smaller. Pediatric ED CT utilization particularly in the adolescent population has increased at a rate far exceeding the growth in ED patient volume, mimicking the adult trend. This increase has occurred despite considerable discussion in the medical literature about the radiation risks of CT in the pediatric population and may reflect increased availability of CT, improvements in CT diagnostic capabilities, and increased desire on the part of physicians and patients for diagnostic certainty. Whether this increased utilization results in improved patient outcomes is uncertain and deserves further study.