Background and Objectives : This study was designed to test whether vena contracta width (VCW) measured by Color Doppler flow could be used for assessing the severity of mitral stenosis. Materials and Methods : Twenty four patients (mean 52 짹 11 years, 15 females) with mitral stenosis who did not have more than mild mitral regurgitation were enrolled in this study. The mitral valve area (MVA) was assessed by one observer with conventional methods such as continuity equation (CE), pressure half time (PHT), and planimetry in parasternal short axis view. The VCW was measured in the apical four chamber view by Color Doppler flow by another observer blinded to the data obtained by conventional methods in the same patients. VCW measurements were compared with MVA by CE, PHT and planimetry. Results: In all patients, mean heart rate was 71 짹 15 bpm. Of the 24 study patients, 9 had atrial fibrillation and 15 had sinus rhythm. The MVA determined by CE, PHT, and planimetry was 1.19 짹 0.42, 1.31 짹 0.53, and 1.27 짹 0.43 cm2, respectively. The VCW at an aliasing velocity of 68 짹 5 cm/s was 1.04 짹 0.30 cm. The VCW had strong correlations with MVA by CE (r=0.902, p<0.001), PHT (r=0.756, p<0.001), and planimetry (r=0.859, p<0.001). The VCW in patients with MVA <1 cm2, 1 to 1.5 cm2, and > 1.5 cm2 calculated by continuity equation method was 0.73 짹 0.18, 1.16 짹 0.19, and 1.32 짹 0.07 cm, respectively. The measurement of VCW with MVA < 1 cm2 by CE were significant different from those of VCW with MVA>1 cm2, p<0.001. The standard error of estimate of the VCW was 0.098 with R valve of 0.948. Conclusion: The VCW is easy to use in clinical practice and provides a reliable assessment of the severity of mitral stenosis when compared to the existing methodology.