OBJECTIVE To describe pulmonary venous flow patterns using transthoracic echocardiograms on children suffering from different congenital heart defects with increased pulmonary flow. METHODS Prospective study and consecutive selection of children suffering from congenital heart defects with increased pulmonary flow. The transthoracic, apical view, Doppler echocardiogram was used, positioning the sample-volume at the lower pulmonary vein, 4mm from its junction with the left atrium. The data analyzed included: dominant systolic or diastolic pulmonary venous flow and atrial contraction waveform characteristics, designated as "A" for absent and "R" for reversed. RESULTS The study included twenty-nine patients with a mean age of 29.9 +/- 58.9 months, suffering from the following congenital heart conditions: interatrial and interventricular communication defects, patent ductus arteriosus, atrioventricular septal defects, total transposition of the great arteries and truncus arteriosus. All the patients presented a continuous pattern of high velocity pulmonary venous flow. Nine patients presented a dominant systolic waveform (31%), eighteen presented a dominant diastolic wave form (62%) and 2 patients had systolic and diastolic wave forms of equal amplitude (7%). Six patients (21%) presented a R atrial contraction waveform and 23 (79%) presented an A atrial contraction waveform. CONCLUSIONS Congenital heart diseases with increased pulmonary flow present a continuous pattern of high velocity pulmonary venous flow with alterations mainly in the atrial contraction reversal pattern.