We report an 80-year-old woman, with pseudoaneurysm of the right proximal subclavian artery despite the absence of a history of trauma. On preoperative examinations, the aneurysm involved to the common carotid arteries. A long temporary bypass using a heparin-coated tube from the right femoral artery to the right common carotid artery was created under low dose systemic heparinization. A Dacron bifurcation graft bypassing was then performed successfully. At surgery for right proximal subclavian artery aneurysm, which often involves the right common carotid artery, intraoperative accident or bleeding can induce brain ischemia. A temporary bypass should be prepared. Although the short temporary bypass from the aorta to the right common carotid artery was reported, this carries the risk of complications due to microemboli. The heparin-coated tube provided excellent anti-thrombosis. Inflow cannulation should be placed at the peripheral artery not the aorta.