BACKGROUND Composite sequential femoro-popliteal-distal bypass is a valuable option for treatment of critical limb ischemia when autogenous vein is limited and an isolated popliteal or distal arterial segment exists. We report a modified technique for composite sequential bypass and the results with its use over a 14-year period. METHODS Twenty-five modified composite sequential bypass procedures were performed on 24 patients to treat gangrene, ischemic ulceration, and severe rest pain. Vein grafts were anastomosed from blind popliteal or blind distal arterial segments above-knee (7) or below-knee (18) to a distal outflow vessel including the below-knee popliteal (1), posterior tibial (5), anterior tibial (7), or peroneal (12) artery. Polytetrafluoroethylene bypass grafts were then placed from a suitable inflow artery to the proximal hood of the vein graft. RESULTS Cumulative primary patency rates were 80% at 3 years, and 65% at 5 years. The limb-salvage rate was 85% at 4 years. Occlusion of the prosthetic segment with a patent distal vein segment was recognized in two patients who presented with less severe recurrent ischemia. Limb-salvage in these patients was achieved by a secondary prosthetic graft to the patent vein graft. CONCLUSIONS Our modified configuration of the prosthetic-vein anastomosis for composite sequential bypass is an alternative to the conventional procedure and may help preserve vein graft patency should the polytetrafluoroethylene graft thrombose.