Transcutaneous oxygen partial pressure measurement (TcPO2) using a polarographic probe heating the skin at 44 degrees C provides informations about the capacity of blood to supply skin with oxygen. As oxygen is necessary for tissue survival, TcPO2 could constitute an adequate parameter for the determination of an amputation level. Among 67 amputations performed between 1983 and, 1984, we included in this study 34 patients (35 amputations), in whom TcPO2 was preoperatively measured (24 males, 10 females, mean age 67 years, range 19-86 years). Twenty two were diabetics. Twenty patients suffered from severe ischemia (stage Fontaine 4); 13 patients suffered from chronic diabetic lesions or/and osteomyelitis and two patients suffered from frostbite. The follow-up period lasted until operative wound was healed or a more proximal amputation was undertaken (mean 2.5 months, range 15 days to 10 months). Five operative wounds did not heal, so that a more proximal amputation was undertaken. TcPO2 was below 20 mm Hg in 3 of these 5 patients. TcPO2 was above 20 mm Hg in 24 among 30 patients in whom operative wound healed. When TcPO2 is above 20 mm Hg, the probability of operative wound healing is 92%. When TcPO2 is below 20 mm Hg, the risk of a more proximal amputation is 33%. Distal systolic blood pressure has no predictive value. It is concluded than when TcPO2 is above 20 mm Hg, the probability of healing of operative wound is clinically acceptable. When TcPO2 is below 20 mm Hg, 1 of 3 patients will be reamputated at a more proximal level, but healing does occur in 66% of patients.