Background: High sensitive C-Reactive Protein (hs-CRP) predicts morbidity and mortality in various clinical conditions. The effect of hsCRP on progression of chronic rheumatic mitral stenosis (CRMS) has not been demonstrated. Methods and results: A total of 132 patients with CRMS (95 female, 37 male) and 145 control (100 female, 45 male) were included in the study. Baseline clinical, echocardiographic, hematologic and hs-CRP measurements were collected prospectively. Mean mitral valve area (MVA) was 1.4 ± 0.3 cm2, mean wilkins valve score value was 8.9 ± 1.7, left atrial diameter was 5.0 ± 0.7 cm, left atrial area was 37.2 ± 12.6 cm2, and systolic pulmonary arterial pressure (SPAP) was 44 ± 11 mmHg in patients with CRMS. The mean levels of hs-CRP value, fibrinogen, and mean platelet volume (MPV) were significantly higher in CRMS group compared to control group. The levels of hsCRP were found to be positively correlated with mean Wilkins valve score value, SPAP, presence of atrial fibrillation (AF), left atrial diameter, left atrial area, presence of LASEC(+), fibrinogen, and MPV and inversely correlated with MVA in patients with CRMS. Linear regression analysis revealed that the hsCRP level independently affects mean Wilkins valve score value, left atrial area (LAA), LASEC(+) and AF in the patients with CRMS. Conclusions: These results suggest that increased hsCRP levels are associated with CRMS severity. These association may be important when treating patients with CRMS. © Springer Science+Business Media, LLC 2008.