Between August 1980 and July 1982, 70 children were operated on for congenital heart defects without the use of cardiac catheterization and/or angiocardiography (7.5% of the total of 929 operations). The diagnosis was established by clinical examination, chest x-ray, electrocardiography, and comprehensive cross-sectional echocardiography. The following lesions were repaired: coarctation of the aorta in infancy (n = 28), total anomalous pulmonary venous drainage (n = 6), aortic valvular/subvalvular lesions (n = 11), mitral and tricuspid valve lesions (n = 4), simple transposition of the great arteries (n = 3), vegetations (n = 3), persistent truncus arteriosus (n = 2), and others (n = 13). Three diagnostic errors occurred, and in four children the initial diagnosis was not complete. No child died as a consequence of an error or incomplete diagnosis, and in only one instance was an inappropriate operation carried out (abdominal coarctation of the aorta). We conclude that operation on selected patients can be safely performed on the basis of noninvasive investigation.