Infrainguinal vein bypass continues to be widely accepted as providing effective palliation for disabling claudication and limb salvage in patients with arterial insufficiency of the lower extremity. The development of lesions that may threaten vein graft patency are presently an inevitable consequence of arterial reconstruction in the atherosclerotic patient. However, long-term patency has been sustained by detection and intervention for inflow, outflow, or intrinsic graft lesions. The excellent secondary (assisted primary) patency rates achieved for both reversed and in situ vein grafts affirm the importance of a noninvasive surveillance protocol and a low threshold for reintervention before actual graft failure.