The endothelial dysfunction (ED) in diabetic foot syndrome (DFS) is manifested in the imbalance between the formation of vasodilating and vasoconstrictive substances, not only in the affected area (lower limb), but in the other areas of the peripheral circulation (skin of dorsum of the hand). The aim of this study was the comparative evaluation of endothelial function in patients with neuropathic and neuroischemic forms of DFS in the remote skin tissue, that is, skin. Laser Doppler flowmetry (LDF) was used to assess skin perfusion. The study was conducted in patients with neuropathic and neuroischemic forms of diabetic foot receiving standard hospital treatment at the surgical ward of complicated forms of diabetic foot syndrome in the St. Petersburg's City Hospital 14. Control group comprised patients with proven absence of manifestations of diabetes mellitus and cardiovascular disease. In patients with neuropathic and neuroischemic forms of DFS the significant decrease in microcirculation in the skin was observed. Assessment of the functional state of endothelium in patients with neuropathic and neuroischemic forms of DFS was conducted using functional tests (cold test and iontophoresis of acetylcholine or nitroglycerine). We found significant decrease in endothelium-dependent and endothelium-independent vasodilatation, which was more prominent in neuroischemic forms of DFS.