Objectives: To measure serum B-type natriuretic peptide, especially N-terminal segment of its prohormone (NT-proBNP) and pulmonary arterial pressure levels and to determine whether NT-proBNP concentrations correlate with pulmonary arterial pressure levels in children before and after adenotonsillectomy. Methods: Twenty children with adenoid and tonsil hypertrophy and 20 healthy subjects were included in the study. Transthoracic echocardiography was performed in all patients to assess pulmonary artery systolic and diastolic pressure with cardiac dysfunction. The NT-proBNP was analyzed for correlation with pulmonary artery pressure. Results: Our results showed that prohormone serum concentrations and pulmonary arterial pressures were significantly higher in the study group than in the control group at the preoperative evaluation. A significant decrease was detected among patients after surgery (p< 0.05). There was no significant difference between the study and control groups for prohormone serum concentration and pulmonary arterial pressure at the postoperative evaluation (p> 0.05). Conclusion: We found increased serum prohormone levels and height pulmonary artery pressures in the children with adenoid and tonsil hypertrophy when comparing with healthy subjects. Our study supported that increased serum prohormone levels and pulmonary artery pressures as a result of adenoid and tonsil hypertrophy are reversible. Pediatric cardiologs and otolaryngologs should keep in mind an increased pulmonary artery pressure during management of children with adenoid and tonsil hypertrophy. Furthermore, Doppler echocardiography may be useful in the monitoring of pulmonary arterial pressure and in the follow-up of surgical outcome of children with adenoid and tonsil hypertrophy. © 2013 Elsevier Ireland Ltd.