Aortobifemoral bypass (AoFB) is the preferred method to provide lower extremity inflow. To determine whether axillofemoral bypass (AxFB) is an acceptable alternative for high-risk patients, we reviewed our results with these two operations. Between 1985 and 1990, 29 axillobifemoral and 5 axillounifemoral bypass procedures were performed preferentially because of severe associated medical illness in patients with severe aortoiliac occlusive disease. During the same interval, 107 patients received an AoFB for pure aortoiliac occlusive disease. Nearly all patients having AxFB and AoFB were heavy smokers, and the two groups had similar rates of hypertension and angina. However, other major risk factors were more frequently found in patients undergoing AxFB. Limb-threatening ischemia was more frequent and femoral artery occlusive disease was more severe in patients having AxFB. Anastomosis to the deep femoral arteries and concomitant infrainguinal bypass were more likely to be required in patients who had AxFB. Life-table patient survival at 3 years was 35% for AxFB versus 91% for AoFB (p less than 0.001). Primary patency at 3 years was 63% for AxFB versus 85% for AoFB (p = 0.032). Secondary patency was 74% for AxFB versus 94% for AoFB (p less than 0.001). However, all revised grafts in both groups were patent at 36 months, and only one revised AxFB graft was an ultimate failure. Limb salvage at 3 years was 76% for AxFB versus 97% for AoFB (p = 0.065). Nineteen of the 22 patients with AxFB who died during follow-up died with patent grafts. Hemodynamic performance of AxFB and AoFB were compared. Mean preoperative ankle-brachial index was higher in AoFB (0.50) than AxFB (0.38, p less than 0.001), but postoperative ankle-brachial index was much higher after AoFB (0.83) than AxFB (0.57, p less than 0.001). Even after adjustment for severity of outflow disease, postoperative ankle-brachial index was much better after AoFB than AxFB. Axillofemoral bypass was performed in older higher risk patients with more severe ischemia than those in the AoFB group. Hemodynamic performance was inferior and graft failure more common after AxFB. However, AxFB provided limb salvage in all but 2 of 22 patients who have died, and no survivor has had amputation because of graft failure. Axillofemoral bypass is an acceptable but hemodynamically inferior alternative to AoFB in properly selected high-risk patients with critical lower extremity ischemia who would likely not tolerate the more durable AoFB.