Below is given a comparative evaluation of the genetic and the epidemiological examination of the cohort comprised by VNIIEF personnel subjected chronically to gamma-neutron ionizing radiation (74 persons), as well as nonirradiated cohort (74 persons). There are obtained data on the influence of the integral genotype structure on the health of an individual in case of occupational irradiation. The epidemiological analysis revealed statistically meaningful differences between the main and the control cohorts in the following five cases: acute respiratory diseases, diseases of upper respiratory tract, brain vessel malfunctions; illnesses connected with vision organs and cardio-vascular system and traumas. In such two cases as diseases of vision organs and cardio-vascular system the morbidity difference should be strictly attributed to the influence of the occupational factor. As a result of the genetic analysis it was shown that carriers of certain alleles of the loci ACP and Gc are credibly more susceptible to a number of diseases, when exposed to gamma-neutron irradiation. Besides, was proven that the occupational irradiation does not aggravate susceptibility to allergies and flew.