Anomalous origin of the right pulmonary artery from the ascending aorta is a rare congenital malformation. Formerly identified at angiography and during surgery, it can now be diagnosed by two-dimensional echocardiography, as was done in the two cases reported here. The first case was a neonate in heart failure in whom echocardiography revealed the anomalous origin of the right pulmonary artery; this diagnosis was confirmed at post-mortem examination. The second case was a 4-month old infant in heart failure; echocardiography displayed the malformation which was confirmed at angiography and surgery. In both cases echocardiography showed discontinuity between the pulmonary trunk and the right pulmonary artery and continuity between the pulmonary trunk and the left pulmonary artery. There also was continuity between the right pulmonary artery and the ascending aorta. Doppler ultrasound showed a systolic and a diastolic flow in the right pulmonary artery and only a systolic flow in the left pulmonary artery. A colour-coded doppler examination in one case confirmed the anomalous origin of the right pulmonary artery and the absence of any other abnormality. Two-dimensional echocardiography combined with colour-coded doppler ultrasound therefore is the method of choice to diagnose anomalous origin of the right pulmonary artery from the ascending aorta.