Coarctation of aorta is rather common congenital cardiovascular defect in the western countries, but it is known to be rare in Korea. And no coarctation of Aorta has been reported and operated upon during early infancy in Korea. During 4 months period from May 1984 to September 1984, four small infants of coarctation of aorta were seen and treated surgically by subclavian flap aortoplasty in Guro Hospital, Korea University. All infants were male, ranging from 7 days to 54 days old [mean 29 days], weighing between 3.2 Kg and 5.0 Kg [mean 4.1 Kg], and all were in congestive heart failure. Examination of the femoral artery pulse gave in all cases clues to the diagnosis. By Two dimensional echocardiogram, detail anatomical features as well as the diagnosis were revealed and associated anomalies, for example, ventricular septal defect could be seen. Besides one case of isolated coarctation of aorta, other three infants had associated VSD. The 3 patients with VSD were treated by pulmonary artery banding in addition to aortoplasty. The postoperative course were smooth in all patients. In conclusion, coarctation of aorta may not be so rare in Korea as we thought previously. The importance of femoral pulse examination can not be overemphasized for the diagnosis. As we experienced, two-dimensional echocardiography in most cases can substitute those invasive examinations such as angiography and catheterization which carry difficulty and risk in infants.