The ideal technique to repair a damaged peripheral nerve is primary repair. Unfortunately, most damaged peripheral nerves have gaps making primary repair impossible. Autologous nerve grafts that are used to repair damaged nerves can either be conventional nonvascularized nerve grafts or vascularized nerve grafts. Vascularized nerve grafts are proposed to be superior to conventional nerve grafts especially in recipient beds that are scarred, with poor vascular supply. One of the disadvantages of vascularized nerve grafts is the limited donor site. It is possible to eliminate this problem by prefabricating vascularized nerve grafts. In this study, to prefabricate a vascularized nerve, segments harvested from left sciatic nerves of 10 Wistar albino rats were implanted on right femoral vessels, and intact right sciatic nerves were used as controls to evaluate the function, electrophysiologic studies, and histopathologic examination, were performed on these grafts 4 weeks after implantation. Prefabricated sciatic nerve grafts showed vascularization, but they did not show compound action potential activity to electrical stimulation and demonstrated diffuse and severe vacuolar degeneration and myelin loss. We were unable to prefabricate a functional vascularized nerve graft by this method.