From 1962 to 1978 1938 reconstructions because of arterial occlusive disease were performed at the Department of Surgery, Städt. Klinikum Karlsruhe. Of these 297 were primary aorto-iliac reconstructions. All latter cases were classified according to morphologic characteristics. The ratio of men to women was 8 : 1, the average age 58,9 years. A comparison of the results in these 227 patients with reconstruction either by endarteriectomy or dacron bypass was made regarding the way of incision. The results show a lower letality of 4,6% when extraperitoneal exposition is used compared to 14,1% when transperitoneal exposition was performed. As there was no difference found in the late results after either method of reconstruction (123 patients were reexamined), extraperitoneal exposition is preferred except in cases with aneurysm and aortic occlusion up to the renal arteries.