HLA alleles have been determined for the first time in individuals from the Chuvashian population by DNA typing and sequencing. HLA-A, -B, -DR, and -DQ allele frequencies and extended haplotypes have also been determined, and the results compared to those for Central Europeans, Siberians and other Asians, Caucasians, Middle Easterners, and Mediterranean peoples. Genetic distances, neighbor-joining dendrograms, and correspondence analysis have been performed. Present-day Chuvash speak an Altaic-Turkic language and are genetically related to Caucasians (Georgians), Mediterraneans, and Middle Easterners, and not only to Central or Northern Europeans; Chuvash contain little indications of Central Asian-Altaic gene flow. Thus, present-day Chuvash who speak an Altaic-Turkic language are probably more closely related to ancient Mesopotamian-Hittites and northern European populations than to central Asia-Altaic people.