Over a 3 1/2 year period, 55 limbs were revascularized with in situ saphenous vein bypass grafts in 49 patients. Ninety-five percent of grafts were constructed in patients with critical ischemia for limb salvage, and 5 percent were constructed for debilitating claudication. The proximal anastomosis was performed in the groin in all patients. The distal graft was taken to the popliteal artery in 45 percent and to a tibial or isolated popliteal segment in 55 percent, with 55 percent of the grafts having single-vessel runoff. The perioperative mortality rate was 7 percent. The primary immediate patency rate was 91 percent and the secondary immediate patency rate was 98 percent at 1 month. The cumulative patency rate at 42 months was 85.4 percent overall, 86.6 percent for the tibial grafts, and 84 percent for the popliteal grafts. The cumulative limb salvage rate was 100 percent for the popliteal grafts, 90 percent for the tibial grafts, and 94.5 percent overall. All of the patients were followed and 3 required secondary revision. In situ vein bypass is a technically demanding procedure that can be performed successfully in high-risk patients with limbs with minimal runoff and can yield very high long-term patency and limb salvage rates in a community hospital setting.