Immune deficiency epidemiological survey covered adult population of the town of Vyshkov in the Bryansk region of Russia referred to the zone of radionuclide contamination hazard after the Chernobyl accident. A total of 3892 subjects were examined for the leading immunopathological syndromes (infectious, allergic atopic, autoimmune, lymphoproliferative) according to a specially devised technique developed in the Research Institute of Immunology in Moscow. Immune deficiency risk group made up 10.25% which is much higher than relevant value for control rural population of the southern Urals exposed to low-dose radiation and of polluted region in the East Siberia. The quantitative analysis indicated more frequent occurrence of infectious and lymphoproliferative syndromes of immune deficiency in the absence of radiation-related allergic diseases in the town of Vyshkov.