METHODS In 40 legs of 35 patients with Fontaine's stage I to IV peripheral arterial occlusive disease aged between 41 and 77 years, tcPO2 and malleolar artery systolic pressure were measured over a period of two weeks. RESULTS It was found that the tcPO2 on the dorsum of the foot varied between 10.2 and 18.9 mm Hg, in the lower leg between 13.4 and 22.0 mm Hg, and in the thigh between 10.8 and 14.5 mm Hg as compared with the baseline value. In contrast, the dorsal pedis and anterior tibial arterial blood pressures showed no significant variation over time. CONCLUSIONS The range of variation of tcPO2 in feet, lower legs and thighs must be taken into account in long-term measurements.