The echocardiogram is the gold standard, in the diagnosis of the hemodynamically significant patent ductus arteriosus (hs-PDA) of the premature newborn (PNB). Type B brain natriuretic peptide (BNP) may be useful in the diagnosis and management of CAP-hs.The objective of the study was to assess the utility of BNP as a marker of hemodynamic overload of the patent ductus arteriosus in newborns with gestational age < 32 weeks or weight < 1500 g, and to identify the best cutoff point for BNP levels that would best predict a PDA with hemodynamic impact requiring pharmacological and/or surgical treatment.Retrospective, observational, and descriptive study of PNB < 32 weeks gestation or weight < 1500 g, in which echocardiogram and BNP determination was performed. Analysis of the global sample and by subgroups, depending on the hs-PDA status was performed.A total of 29 patients were analyzed. A significant correlation was found between the PDA/weight ratio and BNP levels (Spearman: 0.71; 95% confidence interval: 0.45-0.87; p < 0.001). The best BNP cutoff point to predict CAP-hs was 486.5 pg/ml with a sensitivity of 81% and specificity of 92% (p < 0.001).The BNP cutoff point identified in the present study was correlated with the presence of CAP-hs.