Objectives: PA chest X-ray is the first choice for evaluation of the lung pathologies in children. The use of computedtomography (CT) has been increasing due to defensive medicine approaches and diagnostic advantages such as multiplanar imaging. The most important situation in childhood imaging is avoiding high radiation exposure, which is thedisadvantage of CT. In this study, diagnostic coherence between chest X-ray and CT and the necessity of chest CT wereevaluated.Methods: 644 patients under 15 years old who had admitted to emergency room and underwent chest CT betweenJanuary 2017 and January 2019 were enrolled in this retrospective study. 348 of 644 patients had just chest CT withoutchest X-ray. All pathologies in chest CT and chest X-ray were examined by two radiologist (F.E.U, B.O). Lung pathologieswere classified as radiologically. Statistical Package for the Social Sciences (SPSS, version 21 for windows) was used forthe statistical analysis. The coherence between chest X-ray and CT was evaluated with Cohen’s kappa test. P<0.05 wasconsidered.Results: Chest CT was performed only in 0.9% of under 15 years old patients who had chest X-ray between January 2017 and January 2019. Normal radiological findings were found in 288 of 348 patients (83%) who had only CTscanning. There were coherence for all radiological findings (atelectasis, consolidation, ground glass opacity, nodularinfiltration, pneumothorax, pleural effusion, bone fracture, mass and cavitary lesions) in between two methods. In 8patients who had both chest CT and X-ray, cavitary lesion was not detected in chest X-ray (Kappa: 0.490, p=0.002).Conclusion: Patients had mostly normal findings when they were examined by just CT before not underwent chest X-ray.There was a coherence between two examinations in all lung pathologies. Radiation exposure significantly decreaseswhen the patients examined firstly with PA chest X-ray. There are problems such as positioning and inspirium sufficiencyin chest X-ray in children, but it is usually enough for evaluating lung pathologies, as seen in our study. We think that it isappropriate to perform chest X-ray firstly in stable patients. Further, we think that it is also appropriate to perform chest Ctwhen clinical findings was not regress or for excluding additional pathologies.