From October 1990 to May 1993, 19 patients underwent replacement of the transverse aortic arch. [10 men, 9 women, mean age 52.5 years] Underlying diseases were acute aortic dissection [10 cases], chronic aortic dissection [4 cases],and aortic arch aneurysm [ 5 cases]. In 19 patients, 10 underwent partial replacement and 9 underwent total arch replacement. The cerebral protection was achieved by profound hypothermia [rectal temperature,16$^{circ}$ to 2$0^{circ}C$] associated with total circulatory arrest [mean 35.5 minutes]. In one patient, the aortic arch distal to the left common carotid artery was resected with the distal arch being cross-clamped and in another two patients, the selective cerebral perfusion was also applied during the period of total circulatory arrest via innominate artery and left common carotid artery because of longer total circulatory arrest time. Among 14 patients of aortic dissecton, 10 presented hypertension, 1 presented Marfan syndrome, 1 presented pregnancy-induced hypertension and 2 revealed no evidence of hypertension. All of the above 14 patients complained chest pain. Among 5 patients of aortic arch aneurysm, Be het disease was suspected in only one patient and atherosclerotic aneurysm was proved in another 4 patients. The overall hospital mortality was 32% [6/19]. In aortic dissection, the mortality was 43% [Acute aortic dissection 30%, chronic aortic dissection 75%] and in aortic arch aneurysm, the mortality was 0%. Follow-up was done in all survivors for from 7 months to 36 months[mean,17.3%].