Among 814 patients undergoing repair of tetralogy of Fallot with pulmonary stenosis between 1967 and May 1986, transannular patching in the current era was a weak risk factor for death early postoperatively (predicted 30-day mortality, 4% with a transannular patch and 1.4% without) and is not a risk factor for instantaneous risk of death late postoperatively (predicted 20-year survival including early death, 94% with a transannular patch and 96.5% without). Ninety-six percent of surviving patients were in New York Heart Association functional class I at last follow-up, and the slight decline in this percentage as the interval between operation and last follow-up lengthened could have been due to chance alone (p = 0.24) and was no different in patients with a transannular patch. Transannular patching was a risk factor for reoperation for pulmonary regurgitation late postoperatively, but only a 7% incidence within 20 years is predicted when mild residual stenoses are beyond the patch: the incidence rises to about 20% with important distal stenoses. Inferences from the study are relevant to the indications for transannular patching and insertion of allograft semilunar valves at the time of repair.