In 42 amputations (28 below-knee and 14 above-knee), healing of the stump was found to correlate with the pre-operative transcutaneous oxygen pressure (tcPO2) measured at the planned site of incision. Of 31 patients with a tcPO2 of 30 mmHg or more, 27 healed primarily, three had delayed healing and one failed to heal; of seven patients with values between 20 and 30 mmHg three healed primarily and four had delayed healing; and all four patients with a value below 20 mmHg had stumps which failed to heal and needed reamputation. It is concluded that a tcPO2 of 20 mmHg or more at the intended site of amputation indicates that the wound will heal.