We measured the hemodynamic improvement after femorofemoral grafting and determined the five-year cumulative patency rate in 54 consecutive high-risk patients with unilateral iliac artery occlusion who had femorofemoral grafts who were studied with ankle and brachial systolic pressure measurements before and after operation and at six-month intervals. There were two early deaths and seven early graft failures (less than 30 days) with four amputations (all operated on for rest pain). All of the remaining 45 patients' conditions improved clinically and objectively. The resting pressure index (mean +/- SD) in claudicants (n = 23) increased from 0.35 +/- 0.15 to 0.67 +/- 0.20; in patients with severe ischemia (n = 31) it increased from 0.25 +/- 0.15 to 0.50 +/- 0.20. During the follow-up period (six months to ten years), there were eight deaths and 12 late graft failures (greater than 30 days). The late cumulative patency rate was 60% at five years. Hemodynamic improvement parallels clinical success and for these high-risk patients, the femorofemoral bypass is a satisfactory alternative to a more major operation.