Standard knitted Dacron prosthetic grafts in the aortic position have performed well in terms of patency and durability, but require preclotting and lose their pliability with use. In an effort to overcome these problems, a collagen-impregnated double-velour knitted Dacron graft has been developed. This graft is impervious to blood, does not require preclotting, and maintains its pliability. During a 2 and one half year period, 590 of these grafts have been used at our institution for abdominal aortic replacement in both emergent and elective cases. Indications have included aneurysmal disease (67%), occlusive disease (30%), and failed previous aortic graft (3%). A bifurcated graft has been used in most cases (68%). The patient population has included 449 men and 141 women. Their median age is 68 years, with a range from 15 to 91 years. Seventy nine per cent of the patients experienced no perioperative complications. The remaining twenty one per cent have had a variety of complications, most of them cardiac or pulmonary, but none related directly to the graft. Twenty nine patients died in the perioperative period, for a mortality of 4.9 per cent. Late complications have been infrequent and in no cases directly related to the graft. There have been no graft-related late deaths. It is concluded that, at least in this early experience, there are no problems inherent in the use of this graft. Its pliability and the fact that it does not require preclotting are distinct advantages over previous Dacron grafts.