Mitral pressure half-time(PHT) is widely used as an independent measure of mitral valve area(MVA) in patients with mitral stenosis. However, few data exist regarding the effect of mitral regurgitation and aortic regurgitation on the validity of this method. Two hundreds and three patients with mitral stenosis were studied by Doppler echocardiography and 2 dimensional echocardiography(2 DE) to assess whether mitral regurgitation and aortic regurgitation affected the calculation. Ninety patients had mitral stenosis only, 45 patients were combined with mitral regurgtation, 54 patients were combined with aortic regurgitation and 14 patients were combined with both mitral and aortic regurgitation group. Doppler PHT and 2DE estimates of MVA correlated well in total patients(r=0.903) and mitral stenosis only group(r=0.924). Good correlations were maintained in patient subgroups combined with mitral or aortic regurgitation(r=0.867 and 0.911, respectively) and both mitral and aortic regurgitation(r=0.843). Thus, measurement by Doppler PHT may reflect accurately the MVA as determined by 2DE regardless of presence of mitral and/or aortic regurgitation.