A 69-year-old man with right aortic arch was diagnosed as having left lung cancer (cT2aN1M0, cStage IIA) and an aneurysm of an aberrant left subclavian artery. The aneurysm measured 36 mm in diameter and was located 1 cm peripheral from the origin in the area known as "Kommerell's diverticulu Left carotid artery-to-left subclavian artery bypass graft was placed through a left supraclavicular incision prior to thoracotomy. This bypass graft effectively prevented neurological and ischemic complications of the brain and left upper extremity while we safely and successfully performed resection of the aneurysm along with radical surgery for left lung cancer through left thoracotomy. There have been only 10 case reports, including the present case, that have described surgical resection of lung cancer in a patient with right aortic arch. In addition, this is the 1st report to describe simultaneous surgery for both left lung cancer and an aneurysm of an aberrant left subclavian artery in a patient with right aortic arch.