To study the mitochondrial gene pool structure in Yakuts, polymorphism of mtDNA hypervariable segment I (16,024-16,390) was analyzed in 191 people sampled from the indigenous population of the Sakha Republic. In total, 67 haplotypes of 14 haplogroups were detected. Most (91.6%) haplotypes belonged to haplogroups A, B, C, D, F, G, M*, and Y, which are specific for East Eurasian ethnic groups; 8.4% haplotypes represented Caucasian haplogroups H, HV1, J, T, U, and W. A high frequency of mtDNA types belonging to Asian supercluster M was peculiar for Yakuts: mtDNA types belonging to haplogroup C, D, or G and undifferentiated mtDNA types of haplogroup M (M*) accounted for 81% of all haplotypes. The highest diversity was observed for haplogroups C and D, which comprised respectively 22 (44%) and 18 (30%) haplotypes. Yakuts showed the lowest genetic diversity (H = 0.964) among all Turkic ethnic groups. Phylogenetic analysis testified to a common genetic substrate of Yakuts, Mongols, and Central Asian (Kazakh, Kyrgyz, Uigur) populations. Yakuts proved to share 21 (55.5%) mtDNA haplogroups with the Central Asian ethnic groups and Mongols. Comparisons with modern paleo-Asian populations (Chukcha, Itelmen, Koryaks) revealed three (8.9%) haplotypes common for Yakuts and Koryaks. The results of mtDNA analysis disagree with the hypothesis of an appreciable paleo-Asian contribution to the modern Yakut gene pool.