Based upon the investigation of the hemogram, biochemical indices of blood and certain instrumental methods of research in patients with a critical form of obliterating diseases of lower extremity vessels, whose treatment included UVI of auto-blood, the authors have shown pronounced clinical efficiency of the method of treatment resulting in the improvement of theological properties of blood, microcirculation in tissues, less pain syndrome and rapid healing of trophic ulcers against the background of better condition of the patient. The method allowed the time of staying at the hospital to be substantially shortened.