This is a case report of single-stage total thoracic aortic repair by the frozen elephant trunk technique for a 75-yearold female with a complex aortic pathology of mega-aorta extending from the ascending aorta to the descending aorta. We used a Thora flex™ Hybrid device, a frozen elephant trunk device with four branched grafts and the distal stent graft. The distal stent graft was inserted into the downstream descending aorta via an aortic arch and positioned 15 cm beyond the left subclavian artery after total arch replacement had been performed using a four-branch graft. The postoperative course was unremarkable with no complications. A post procedural computed tomography scan demonstrated complete exclusion of the descending thoracic aneurysm without endoleak. Therefore, fixing the whole mega-aorta in a single stage using the frozen elephant trunk was effective and safe.