Background:Chest X-ray(CXR) is commonly used as a first line imaging method to diagnose the reason of respiratory distress in NICUs.Lung ultrasound is a new diagnostic tool for lung imaging.Objectives:We aimed to determine the decrease in the number of CXRs on the first day of life in newborns with respiratory distress,with the use of lung ultrasonography.Methods:From January 2019 to June 2020,104 newborn infants hospitalized in the NICU with respiratory distress on the first day of life enrolled in this study(ClinicalTrials.govIdentifier NCT04722016).We used ultrasound as the first line technique for lung imaging.CXR was taken to determine endotracheal tube and umbilical catheter position or if considered necessary by the physician in charge of the infant.We calculated decreased number of CXR for every patient and evaluated the estimated decrease in radiation exposure.Results:104 neonates with median 36 weeks(25-40)gestational age and birth weight 2410gr(600-4100) enrolled in the study.Seventy(67,3%)of these babies were male.In the study group,24(23,1 %)patients were diagnosed with respiratory distress syndrome(RDS),49(47,1 %) patients with transient tachypnea of newborn(TTN),27(26 %) with pneumonia,4(3,8 %)with congenital heart diseases.Lung ultrasonography were performed 210 times for all infants,but CXRs were performed a total of only 107 times.CXR wasnot taken in 27 of the patients with a diagnosis of TTN,in 2 of the patients with a diagnosis of congenital pneumonia,and in one of the patients with congenital heart disease.The rate of patients who have never had a chest x-ray was 28,8%.Conclusions:We observed that usage of lung ultrasonography decreased the number of chest X-ray and radiation exposure in newborns with respiratory distress.