Patients with complete interruption of the aortic arch (IAA) very rarely reach late adulthood without having undergone surgical intervention. Only a few cases of IAA in adults have been reported in the medical literature. In this case report, we present a late diagnosis of interrupted aortic arch in a 68 year-old male. Our patient was relatively asymptomatic until he presented with fatigue after walking quickly. A guidewire could not be passed to the aortic arch via the femoral approach; descending thoracic aortography revealed complete occlusion of the descending thoracic aorta. Cardiac catheterization via the right brachial artery confirmed the diagnosis of a complete interruption of the aortic arch distal to the left subclavian artery and showed distinct collateral circulation predominantly via the internal mammary arteries. Also, magnetic resonance angiography showed cuttings that reveal the interruption in the aortic arch and the prominent collateral vessels to the descending aorta. This case report was also interesting in that pressure measurements at a proximal point of the interrupted aortic arch were not hypertensive. Using both catheters, placed proximally and distally to the point of the interruption, by simultaneous pressure measurement, it was measured as 120/75 mm Hg at the proximal point, 60/40 mm Hg at the distal point. (Cardiol J 2011; 18, 6: 695–697)