Many techniques have been proposed to help the surgeon select the most distal amputation level that will heal. Skin blood flow measurement with xenon-133 (133Xe) is one of the best documented predictors of amputation healing, but the lowest flow consistent with healing has not been agreed upon. Our early experience with the method is reported. Skin blood flow was measured in 16 patients undergoing 17 lower extremity amputations. Twelve amputations healed (mean skin blood flow 3.69 +/- 2.73 ml/100 g of tissue/min) and five failed (mean skin blood flow 0.80 +/- 0.61 ml/100 g of tissue/min) (P less than 0.05). No amputation healed if the skin blood flow was less than 1.0 ml/100 g of tissue/min. A skin blood flow above 1 ml/100 g of tissue/min, measured with 133Xe, may be a useful guide to the level at which to amputate while minimizing unnecessary proximal amputation, but the method requires further prospective evaluation.