Pulmonary venous flow as assessed by Doppler echocardiography is a current topic of investigation. Pulmonary venous flow has been used recently as part of a comprehensive assessment of left ventricular diastolic filling dynamics in restrictive myocardial diseases and constrictive pericarditis. Abnormalities of flow have been described in dilated cardiomyopathy, congenital heart disease, and arrhythmias. With the advent of transesophageal echocardiography, pulmonary venous flow can be readily obtained in all patients by pulsed-wave Doppler echocardiography. Recently, it has been used to assess the severity of mitral regurgitation and to estimate mean left atrial pressure. This article emphasizes the utility, physiology, and technique of measuring pulmonary venous flow with Doppler echocardiography in health and in disease.