Monitoring of transcutaneous perfusion pressure of tissue oxygen (tcpO₂) is a simple, non-invasive method performed in diagnostic process of chronic diabetic complications. Primary, tcpO₂is used as an indicator of microcirculatory function. Properly placed and fixed Clark electrode is able to detect with high accuracy partial oxygen pressure on the skin surface by polarographic system of dissolved oxygen from capillary bed through tissues to upper layers of the skin. The microcirculation function is influenced by macrocirculation, thus, tcpO₂is a suitable parameter in diagnosis of peripheral arterial obliterative disease or other vascular pathologies. Combination of tcpO₂monitoring and skin perfusion pressure by laser Doppler technique gives us information not only about nutritive capillary flow, but also about vessels which precede capillary bed. The article discusses current guidelines for measurement of tcpO₂and evaluation of the results. Also reviews the results of recent studies which are interested in the use of tcpO₂in diabetic patients.