Chest X-ray (CXR) is commonly used as a first-line imaging method to determine the cause of respiratory distress in NICUs. The aim of the study was to retrospectively assess the decrease in the number of CXRs performed due to the use of lung ultrasonography on the first day of life for newborns with respiratory distress. Infants who were admitted to the NICU on the first day of life due to respiratory distress were enrolled in this study (ClinicalTrials.gov identifier NCT04722016) and divided into two groups: the study group (n = 104) included patients born between January 2019 and June 2020, and the historical control group (n = 73) included patients born between June 2017 and December 2018. As a first-line technique for lung imaging, only CXR had been used in the historical control group, whereas ultrasound had been preferred in the study group. The radiation dose to the newborns and the number of CXRs performed in the first day of life were compared between the two groups. Significant reductions in the number of CXRs performed and radiation exposure were observed in the study group. The radiation dose decreased from 5.54 to 4.47 mu Gy per baby when LUS was routinely used. The proportion of patients who underwent CXR decreased from 100 to 71.2%. Conclusion: We observed that using lung ultrasonography as a first-line evaluation method in neonates with respiratory distress decreased both the number of CXRs performed and radiation exposure. What is Known: center dot Chest X-ray is commonly used as a first line imaging method to diagnose the reason of respiratory distress in NICUs. center dot Lung ultrasound is a new diagnostic tool for lung imaging. What is New: center dot With the use of lung ultrasonography, radiation exposure of both newborns and healthcare workers can be reduced. center dot This retrospective study revealed that most of the babies with respiratory distress were treated without CXR.