The authors sought to create a saphenous vein interposition graft to be used in cerebral bypass procedures that would be more physiologically appropriate than standard vein grafts and would provide a better match between the graft and recipient vessels at the anastomotic sites. The saphenous vein graft was prepared by lysing the valves with a valvulotome. The blood flow could then be reversed in the vein, allowing it to be used in either direction as a bypass graft. An illustrative case including angiograms that confirm good patency and blood flow through the reversed-flow bypass graft is presented. It is concluded that the reversed-flow saphenous vein graft provides a more physiologically suitable conduit than standard vein grafts. Lysis of the valves allows the graft to be used in an orientation that takes advantage of the natural tapering of the vein to produce a better match with the recipient vessels at the anastomotic sites. Minimizing diameter changes at the proximal and distal anastomoses helps reduce turbulence, which has been implicated as a cause of early graft failure and thrombosis.