We report a 65-year-old female who had a extensive thoracic aneurysm from ascending aorta to descending thoracic aorta. The patient underwent a graft replacement of ascending aorta and aortic arch using modified elephant trunk method. The surgery was carried out through median sternotomy with profound hypothermia and selective cerebral perfusion. Postoperatively, the patient was recovered without any complications except bronchial asthma. Postoperative chest computed tomography showed that the surrounding space of the elephant trunk vascular graft inserted into distal arch and descending aneurysm was mostly occupied with thrombus. Therefore, we considered that the second operation on the descending aorta is not necessary at this point and careful attention to the size and shape of the descending aneurysm should be paid.