In thirty six cases of Tetralogy of Fallot who underwent complete total correction from 1965 to 1975 at Severance Hospital, Yonsei University College of Medicine, the preoperative and postoperative plain chest radiographic findings were analyzed and compared each other. The clinical and operative findings were reviewed for the details of radiologic evaluation. The clinical and operative results are as follows; 1. The patients ranged in age from one to thirty years at the time of operation and had main symptoms of dyspnea, cyanosis, upper respiratory infection, squatting and clubbing in descending order. 2. In almost cases, the postoperative Hgb, Hct., arterial oxygen saturation and right ventricular systolic pressure are much improved within normal range. 3. In all cases except one with muscular septal defect of ventricle, membranous defects are noticed and in 18 cases the size of defect is above 3cm2. 4. In pulmonary stenosis, combined type is in 19 cases, infundibular one in 10 cases and valvular one in 7 cases. 5. Combined anomalies are artrial septal defect in 4 cases, rightside aortic arch in 4 cases, persistent foramen ovale in 4 cases and aortic insufficiency in 3 cases. Plain chest radiographic findings are is follows; 1. In the immediatlly postoperative periord, cardiothoracic ratio was above 0.55 a stastically significant in 24 cases which measured and it was more increased in the postoperative one or two month. Thereafter, it was maintained with stable size. 2. Preoperatively elevated cardiac apex, indicative of right ventricular enlargement show no significant change in the postoperative periord. 3. Preoperative pulmonary outflow tract appears concave in 21 cases and it pappears flat or convex in the immediatley postoperative periord in 217 cases, suggesting significant posoperative change. 4. In 23 cases, preoperative pulmonary vascular markings are decreased to slight to moderate degree. They are markedly decreased in 25 cases in the immediat y postoperative periord and gradually increased or within normal range from the postoperative one month. 5. In plain chest radiographs, the incidence of mediastinal widening due to hemorrhage when operation and pulmonary congestion in lower lung fields between immediately postoperative periord and postoperative one month.