BACKGROUND Computerized Tomography (CT) scan is gaining more importance in the initial evaluation of patients with multiple trauma, but its effect on the outcome is still unclear. Until now, no prospective randomized trial has been performed to define the role of routine chest CT in patients with blunt trauma. OBJECTIVE In view of the considerable radiation exposure and the high costs of CT scan, the aim of this study was to assess the effects of performing the routine chest CT on the outcome as well as complications in patients with blunt trauma. METHODS After approval by the ethics board committee, 100 hemodynamically stable patients with high-energy blunt trauma were randomly divided into two groups. For group one (control group), only chest X-ray was requested and further diagnostic work-up was performed by the decision of the trauma team. For group two, a chest X-ray was ordered followed by a chest CT, even if the chest X-ray was normal. Injury severity, total hospitalization time, Intensive Care Unit (ICU) admission time, duration of mechanical ventilation and complications were recorded. Data were evaluated using t-test, Man-Whitney and chi-squared test. RESULTS No significant differences were found regarding the demographic data such as age, injury severity and Glasgow Coma Scale (GCS). Thirty-eight percent additional findings were seen in chest CT in 26% of the patients of the group undergoing routine chest CT, leading to 8% change in management. The mean of in-hospital stay showed no significant difference in both groups with a P value of 0.098. In addition, the mean ICU stay and ventilation time revealed no significant differences (P values = 0.102 and 0.576, respectively). Mortality rate and complications were similar in both groups. CONCLUSIONS Performing the routine chest CT in high-energy blunt trauma patients (with a mean injury severity of 9), although leading to the diagnosis of some occult injuries, has no impact on the outcome and does not decrease the in-hospital stay and ICU admission time. It seems that performing the routine chest CT in these patients may lead to overtreatment of nonsignificant injuries. The decision about performing routine CT scan in a trauma center should be made cautiously, considering the detriments and benefits.