Aim: To explore NT-proBNP as biomarker for pulmonary hypertension (PH) in infants with respiratory syncytial virus infection (RSVI). Patients & methods: We prospectively enrolled 93 healthy infants with RSVI aged 1–12 months. NT-proBNP determination and echocardiography were performed at admission. Results: PH was found in 22% of patients and associated with a severe course of the disease. NT-proBNP >1635 pg/ml resulted an independent predictor for PH (odds ratio: 16.46 [95% CI: 4.10–66; p < 0.001]). The diagnostic performance of NT-proBNP to detect PH in RSVI was high (area under receiver operator curve of 0.932 [95% CI: 0.883–0.981; p < 0.001]). Conclusions: The presence of PH in healthy infants with RSVI is associated with worse outcomes. NT-proBNP resulted an accurate biomarker for PH in this setting.