Long-term results and postoperative hemodynamic findings were reviewed in 144 cases of tetralogy of Fallot. A correlation was found between the late clinical status of patients and the postoperative hemodynamic findings. The mortality in our series of patients followed for 10 years was 6.25%. Each of the deaths occurred in the group with unsatisfactory postoperative hemodynamic findings. An ideal late clinical result can be anticipated in most patients with excellent or satisfactory postoperative hemodynamic findings. The greater the deviation from normal hemodynamic findings, the worse the prognosis. From the excellent group to the unsatisfactory group, the incidence of late ideal result decreased from 95% to 61.1%, while the incidence of poor result increased from 0% to 27.8%. Among various factors in patients in the unsatisfactory hemodynamic group, right ventricular outflow tract obstruction seems to have the worst late result. A large right ventricular-pulmonary artery pressure gradient was noted in three of four who died suddenly. The late result of patients with a small shunt (pulmonary blood flow/systemic blood flow < 2) seems acceptable; the decision to reoperate in these patients should be made very cautiously.