Over a 2.5-year period, 16 consecutive infants were prospectively diagnosed as having total anomalous pulmonary venous drainage. The sites of drainage were cardiac (to the coronary sinus) in four patients, supracardiac in nine, infracardiac in two and mixed in one patient. In every case, two-dimensional echocardiography with color flow imaging enabled complete and correct diagnosis of the sites of drainage and the presence or absence of pulmonary venous obstruction. The echocardiographic findings were verified at surgery or autopsy in all. Color flow imaging rapidly provided information about the direction and mean velocity of flow through abnormal vascular structures in any two-dimensional echocardiographic plane. It facilitated the acquisition of quantitative velocity information with standard Doppler ultrasound techniques by identifying areas of high velocity or turbulent flow and was invaluable in the assessment of anomalous pulmonary venous drainage occurring either as an isolated anomaly or in conjunction with complex intracardiac lesions.