Abstract An experimental study in dogs was designed to measure the hemodynamic effects of a distal arteriovenous fistula in conjunction with a proximal venous autograft. Although use of the fistula achieved 100% autograft patency, several potentially detrimental factors were documented. Distal arterial flow was reduced in all animals, and did not correlate fistula size. Flow through the distal artery was directed in a retrograde manner in five of the ten animals. Proximal and distal femoral arterial pressures were significantly reduced when compared with control pressures. The potential ischemic effect of these changes was reflected in a reduced peripheral skin temperature. Distal femoral venous pressure was significantly elevated and resulted in limb edema. These detrimental side effects of the arteriovenous fistula, coupled with the requirement for a second operation for fistula repair, would seem to outweigh anticipated benefits in improved graft patency.