Objective: Research the value of plasma NT - ProBNP in diagnosing acquired heart diseases in children. Objects and methods of the study: Cross-sectional descriptions of 107 patients included myocarditis, dilated cardiomyopathy, supraventricular tachycardia, and Kawasaki disease at the Vietnam National Children's Hospital. Quantify plasma NT- ProBNP concentrations and compare between these pathological groups and the control group. Results: NT-ProBNP concentrations in cardiovascular diseases were higher than in the control group with a statistically significant difference (p<
0.05). NT-ProBNP concentration was highest in the myocarditis group, followed by supraventricular tachycardia and dilated cardiomyopathy, and lowest in the Kawasaki group (p <
0.05). The optimal cut-off points of NT-ProBNP in diagnosing myocarditis, dilated cardiomyopathy, and Kawasaki are 1195, 943.6 and 176.4 pg/ml, respectively. NT-ProBNP concentration in the group with systolic dysfunction (EF<
50%) was statistically significantly higher than the group with normal systolic function (EF≥50%) with p<
0.001. Conclusion: NT-ProBNP concentrations increase in some acquired heart diseases such as myocarditis, dilated cardiomyopathy, supraventricular tachycardia, and Kawasaki. NT-ProBNP concentration correlates with left ventricular systolic function