To determine whether pulmonary venous flow measured by transesophageal Doppler echocardiography can be used to estimate mean left atrial pressure (LAP), we prospectively studied 12 consecutive patients with sinus rhythm undergoing percutaneous mitral balloon commissurotomy for their severe mitral stenosis (mitral valve area < 1.5 cm2). We correlated Doppler variables of pulmonary venous flow and the mean LAP measured by left atrial catheterization. Among the variables of the pulmonary venous flow, the systolic fraction (i.e., the systolic velocity-time integral expressed as a fraction of the sum of systolic and early diastolic velocity-time integral) correlated significantly with mean LAP (r = -0.71, p < 0.05) and mitral valve area (r = 0.64, p < 0.05). Peak velocity and velocity-time integral in systole also significantly correlated with mean LAP (r = -0.66, r = -0.67 respectively, p < 0.05). We conclude that the more severe the degree of mitral stenosis in patients with sinus rhythm, the less systolic pulmonary venous flow in severe mitral stenosis.