Between 1974 and 1983, 380 consecutive patients with tetralogy of Fallot underwent surgery. In 73 patients, undergoing palliative surgery, the operative mortality and late mortality was 6.8%. Twenty-five of these patients have undergone subsequent complete repair, while 38 are awaiting correction. During the last 4 years we preferred operative procedures with enlargement of the right ventricular outflow tract (80%) to shunt operations (20%). In contrast to shunts, enlargement of the outflow tract induces a symmetrical growth of hypoplastic pulmonary arteries without the risk of acquired pulmonary atresia or peripheral stenosis at the site of anastomosis. Three hundred twenty-nine patients have undergone repair. In 101 patients, who had palliative operations before complete repair, the operative mortality was 12.9% and late mortality 2.9%. Those patients undergoing repair as a first operation had an operative mortality of 8.8%, and a late mortality of 1.3%. In the last 5 years the operative mortality for all patients, whether or not they had had previous palliative surgery, was 4.7%. The incidence of transannular outflow tract patching was not greater in children less than 2 years of age (16.9%) than in older children, 2 to 14 years of age (16.5%). However, in our experience the requirement for subvalvular outflow patches was higher in younger children (52.1%) than in the older children (34.1%). Because of this high incidence, particularly in younger patients, we have now begun to repair tetralogy of Fallot using the transatrial approach, thus reducing our use of subvalvular patches.(ABSTRACT TRUNCATED AT 250 WORDS)