Background: Critical coarctation of the aorta is the most common congenital heart disease with ductal-dependent systemic circulation. In severe forms, this disease represents a critical condition, which can become life-threatening. The aim of this study was to evaluate the usefulness of different echocardiographic parameters in the prediction of aortic coarctation in newborns. Material and method: This is a retrospective study performed by reviewing echocardiographic images of both pre-term and full-term newborns presented with aortic coarctation to the emergency room of a clinic of pediatric cardiology. Based on echocardiographic measurements, both the common carotid artery-subclavian artery index (CSAi) and the aortic isthmus-descending aorta index (I/D) were calculated. Results: Fifty-two newborns presented in acute settings with aortic coarctation and were included in the study, divided into: subgroup 1 (n = 26) – ductal-dependent aortic coarctation; subgroup 2 (n = 2) – non-ductaldependent aortic coarctation; and subgroup 3 (n = 24) – unconfirmed aortic coarctation. ROC analysis identified a cutoff value of 1.37 for the CSAi index and a cutoff value of 0.46 for the I/D index as being associated with the highest predictive power for the diagnosis of aortic coarctation. Conclusions: The CSAi and I/D indices are simple and accessible echocardiographic parameters that can provide supplemental information for the pediatric cardiologist in acute cases of newborns with suspicion of aortic coarctation. These new indices can contribute to the decision-making process in case of pre-term and full-term newborns with suspicion of coarctation of the aorta, independent of the presence of persistent ductus arteriosus.