Various models have been proposed to examine blood-prosthetic materials interactions in terms of the effect of the prosthetic material on platelet structure and function, blood coagulation and fibrinolysis, and tissue infiltrates (cellular or acellular). In addition, these models have been used to examine the change in the graft surface over time. Particular difficulties in examining graft-materials interactions include species differences, short residence time for blood-materials interactions with commonly employed short grafts, and length of study limitations with ex vivo shunts. In this paper we report a canine, carotid-aorta subcutaneous prosthetic graft model. The specific advantages of this model are the length of the graft, which allows prolonged contact of blood with the prosthetic surface; the subcutaneous location of the graft, which allows repeated sampling of blood along the graft; and the healing characteristics of canine grafts. We selected the canine model because the healing characteristics are morphologically similar to those in humans in that endothelialization of the prosthetic surface is limited. Other models, such as the pig, are favored for use when examining blood coagulation, platelet, or fibrinolytic studies; however, these models can fully endothelialize prosthetic surfaces.