High frequencies of HLA-A2, -A3, -A9, -B7, -B13, -Bw35, and -Dw3 antigens were found in Sysolian and Udorian Komi (from Vizinga and Koslan, respectively), as well as in Zyuzdian Komi-Permyaks. In some populations, high frequencies of HLA-A10, -A28, -B21, -B27, and -B40 antigens were also found. Similarity in both gene frequency patterns and heterozygosity level was noted between these populations and the population of more western European regions, as well as Finno-Ugric nations. Frequencies of some alleles, e.g., HLA-B8 -B12, -B16, and -B18, were found to be intermediate between the corresponding estimates for Mongoloids and Caucasoids. The Mongoloid influence on the gene pool is expressed in increased HLA-B27, -B40, -Cw2, -Cw3, and -Cw4 frequencies. The frequencies of HLA-A3, -A28, -B7, -B13, and -B35 antigens are higher, and that of HLA-B5 is lower, than the respective frequencies in both Caucasoids and Mongoloids. This reflects the specificity of the ancestral group, whose peculiarities cannot be attributed exclusively to the results of Caucasoid-Mongoloid intermixing. The high level of genetic differentiation of Komi ethnographic groups (F st = 0.0188 +/- 0.0045) is emphasized. The characteristics of distribution of HLA antigens and haplotypes are explained in terms of the ethnogenesis of the Komi; markers for their constituent ethnic components were found.