PURPOSE To evaluate the 15-year trend in the use of computed tomography (CT) in hospitalized pediatric trauma patients admitted to Harborview Medical Center (HMC) from 1996 to 2010. MATERIALS AND METHODS This Health Insurance Portability and Accountability Act-compliant retrospective study was approved by the institutional review board. The requirement for informed consent was waived. The HMC trauma registry was linked to the billing department data, and patient and injury-related characteristics were extracted, in addition to type and frequency of CT procedures. Patients discharged from the emergency department and patients hospitalized for less than 24 hours were not included in this study. Patients were classified into three categories according to age: 0-14 years, 15-18 years, and 19-54 years (reference group). Multivariate negative binomial regression was used to compare CT usage among different age groups by adjusting for patient sex, race and/or ethnicity, insurance status, mechanism of injury, injury severity, final disposition (dead vs alive), and year of admission. The trend for CT use in children and teenagers was also evaluated. RESULTS A total of 64 425 trauma patients 0-54 years of age were admitted during the study period. Compared with CT usage in adults 19-54 years old, usage in children up to 15 years of age was significantly lower for spine (incidence rate ratio [IRR], 0.89; 95% confidence interval [CI]: 0.85, 0.92), maxillofacial (IRR, 0.89; 95% CI: 0.81, 0.97), and thoracic (IRR, 0.91; 95% CI: 0.84, 0.99) CT. Increased use of head CT was observed in children up to 15 years old (IRR, 1.09; 95% CI: 1.05, 1.13) and 15-18 years old (IRR, 1.08; 95% CI: 1.04, 1.13). From 2008 to 2010, usage rates in children up to 15 years old and 15-18 years old was relatively unchanged or slightly decreased for almost all CT types. CONCLUSION A decreasing or unchanged trend was observed in CT usage in hospitalized pediatric trauma patients in recent years. © RSNA, 2013.