Five infants who underwent direct reimplantation or redirection of an anomalous left coronary artery from the pulmonary artery to the aorta were studied. There were no deaths from the procedure. Anastomoses were patent at a mean follow up of 33 months. Left ventricular angiograms before and after operation were digitised frame by frame. Analysis of wall motion showed considerable generalised hypokinesia with no change in cavity shape before operation. After reimplantation there was a significant improvement of global ventricular function as assessed by ejection fraction and end diastolic shape index. There was also a tendency for the shape index change to increase; this was compatible with better global systolic function. Three of the four patients who were restudied showed normal isometric and contour wall motion plots. One child, the oldest at the time of operation, still showed asynchronous onset of contraction and isovolumic relaxation. The procedure offers a low risk of mortality and a high rate of patency of the anastomosis. Improvement of ventricular function can be remarkable and its extent cannot be assessed simply by ejection fraction measurements.