Twenty-six patients undergoing below the knee amputation for ischemic disease of the lower part of the leg had skin blood flow determinations made at the level of the amputation. Flow was measured using the 133Xe clearance technique preoperatively as well as at four and eight weeks after amputation. Amputation was performed using the standard long posterior flap technique, and patients were treated with either an immediate postoperative prosthetic fit or a controlled environment treatment system. Healing occurred primarily in 19 patients; a local below the knee revision was required in two and an above the knee revision in one patient. Flow was lower than in the nondiseased control group in almost all instances preoperatively, but no definite level below which healing would not occur was identified. Postoperatively, skin flow increased in all instances and had reached levels equal to that for the normal control group by eight weeks or sooner. This suggests that, in many instances of nonhealing, local below the knee revisions may be successful without requiring the higher above the knee procedure. No significant differences were noted between patients with diabetes and those without diabetes or either method of postoperative treatment in terms of healing or cutaneous flow.