Controversy exists as to what transcutaneous oxygen (P(tc)O2) levels are required for wound healing and what role hyperbaric oxygen has for this. Current information suggests that 30 to 40 mmHg juxta-wound oxygen tensions in room air are required. We recorded P(tc)O2 measurements in room air and with hyperbaric oxygen in 190 patients with foot wounds; then looked retrospectively and prospectively whether there was any effect on healing. Transcutaneous oxygen measurements under hyperbaric oxygen conditions defined a responder group (P(tc)O2 > 200 mmHg) with a sensitivity of 0.80 and a positive predictive value of 0.88 for healing, regardless of room air measurements when hyperbaric oxygen was used as an adjunct to wound management. This information helps to objectify the indications for hyperbaric oxygen and predict healing especially in those patients with problem wounds of the foot and ankle.