Coarctation of the aorta is rare condition among the congenital cardiovascular defects in Korea. We experienced one case of coarctation of the aorta [postductal type], which was successfully corrected with Dacron graft. This 20 year old man was admitted to our hospital for evaluation of hypertension in the upper extremities and frequent occipital headache of 2 month duration. On physical examination, grade II systolic murmur was heard over the apex and mid back, but thrill was not palpable. Blood pressures were measured at both extremities, its values were 190/70mmHg. in the arms and 120/60mmHg in the legs. Routine chest roentgenogram showed the dilated left subclavian artery high on the left mediastinal border and associated with left ventricular prominence, but notchings of lower border of rib was not seen. Electrocardiogram also showed left ventricular hypertrophy. Final Pre-operative diagnosis was made by the aortic catheterization and aortography, which showed the typical configuration of postductal type of coarctation with poststenotic dilatation of aorta. Under the moderate hypothermia by surface cooling, coarcation was resected 3.5cm in length and then Dacron graft was inserted. After prosthetic correction, blood pressures were recorded 120/60mmHg in arms and 160/120mmHg in legs. The post-operative course was uneventful.[KTCS 1978;1:69-74]