Although the efficacy of treatment for aortic dissecting aneurysms has markedly improved in recent years, stable surgical results have not yet been obtained, the operative mortality rate being still high. We used the method of intralutninal ringed graft implantation, which has recently been attracting attention, in six patients with aortic dissecting aneurysms (Group I). The results were compared with those of surgery using low porosity woven Dacron grafts undertaken in the same period in another six patients with aortic dissecting aneurysms (Group II). Group I was comprised of two type I and four type III patients, five men and one woman, ranging in age from 33 to 64, with an average of 51. All underwent surgery in the chronic stage. Group II was comprised of one case of type I, two of type II and three of type III. The patients were five men and one woman, ranging in age from 35 to 70, with an average of 49. Surgery was performed in the acute stage in three and in the chronic stage in three.<br> Operative death occurred in two patients in Group I (renal insufficiency, arrhythmia) and in one in Group II (peritonitis). Postoperative death in the follow-up period occurred in one patient in Group I (graft obstruction) and in one in Group II (encephalopathy). As complications related to the graft, graft obstruction due to mycotic infection occurred in one patient and leakage from around the graft in two in Group I, whereas there were no such complications in Group II. The duration of aortic blockade tended to be shorter in Group I. There were no cases of hemorrhage in either group. Thus, intraluminal ringed graft implantation proved superior in its technical simplicity and lower association of hemorrhage in the anastomosed area. Further development of devices and training, however, are necessary for applying the graft to the optimal site in the aorta.