The pre and postoperative chest roentgenograms and angiocardiograms were reviewed in 108 patients who had undergone complete surgical correction for Tetralogy of Fallot. Almost all postoperative chest roentgenograms showed increased cardiac size and increased prominence of the main pulmonary artery segment. The degree of postoperative cardiomegaly or outflow tract prominence could not be significantly correlated with peak right ventricular systolic pressure, size of residual shunt or residual gradient across the right ventricular outflow tract. Postoperative residual anatomic abnormalities may be demonstrated angiocardiographically in both patients with clinically acceptable results and those with poor results. Among the most common are residual ventricular septal defects, irregularities at the site of the ventricular septal defect patch, hypokinesia or akinesia at the ventriculotomy site, adherence of the outflow tract to the sternum, dilatation of the outflow tract and main pulmonary artery after outflow tract reconstruction, or residual pulmonary valvular stenosis. Nine right ventricular aneurysms were found among 7 of 76 patients with postoperative angiocardiograms (13.8%). Six of these were secondary to infundibulectomy and ventriculotomy. The right ventricular pressures were elevated in each. The diagnosis of postoperative aneurysm of the outflow tract requires cardiac catheterization and angiocardiography. Even after these are done, it is often difficult to differentiate between a true and false postoperative outflow tract aneurysm.