This study is designed to evaluate the N-terminal pro-BNP (NTproBNP) levels in patients with mitral stenosis (MS) and its possible correlation with clinical and echocardiographic parameters of the disease. The study group consisted of 29 patients with isolated MS (patients with greater mild regurgitation were excluded) and 20 normal control subjects of similar age and gender distribution. Blood samples for NTproBNP were collected at the time of clinical and echocardiographic examination. NTproBNP levels were elevated in patients with MS compared to controls (325 +/- 249 pg/dL [19.9-890] versus 43 +/- 36 pg/dL [5.76-193.3], P < 0.001). Patients with atrial fibrillation had significantly higher NTproBNP levels compared to those with sinus rhythm (561 +/- 281 pg/dL versus 254 +/- 194 pg/dL, P = 0.044). MS patients with sinus rhythm also had higher NTproBNP levels compared to controls (254 +/- 194 pg/dL versus 43 +/- 36 pg/dL, P = 0.00011). NT pro BNP levels correlated to the LA (R = 0.73, P < 0.0001) and RV (R = 0.41, P = 0.042) diameters, mitral valve area (R =-0.45, P = 0.025), mean mitral gradient (R = 0.57, P = 0.003), peak PAP (R = 0.7, P = 0.03), and NYHA functional class (R = 0.61, P = 0.007). In conclusion, serum NTproBNP levels correlate well with echocardiographic findings and functional class in patients with MS and can be used as a marker of disease severity. Additionally, it may have a potential use as an additional noninvasive and relatively cheap method in monitoring disease progression especially in patients with poor echocardiographic windows.