Between Nov. 1981 and Dec. 1990, seventy-seven patients underwent surgical repair for abdominal aortic aneurysm (56, non-ruptured and 21, ruptured). There were no operative and hospital deaths in the non-ruptured group and 4 deaths (19%) in the ruptured group. To improve operative results by means of decreasing hemorrhagic blood loss and operative time, we have ameliolated some points of the technical procedures as follows. Dissection of the perianeurysmal tissue was limited to only the neck and anterior peritoneal surface of the aneurysm. Taping to keep the aorta and distal iliac artery was not applied and vascular clamps were placed without dissection of the posterior walls of the aorta and distal arteries. Proximal anastomosis of the Y-vascular prostheses were performed by the inclusion technique. The end-to-side method was used in distal anastomosis to the external iliac arteries routing behind the ureter. Even when aneurysmal dilatation involved the common iliac arteries, the orifices of the common iliac arteries were closed by continuous sutures bilaterally. In ruptured cases too, this standard technique was used without application of special means for proximal cross-clamping. Postoperative arteriography or enhanced computed tomography reveald thrombosis and reduction in size of residual aneurysm of the common iliac artery. By these improved surgical techniques, 25 cases (45%) of the 56 non-ruptured group had surgical correction of the abdominal aortic aneurysm without using homologous blood transfusion. Cumulative 5-year survival rate by Kaplan-Meier method of non-ruptured and ruptured group was 87% and 49% respectively.