We present novel data on mitochondrial DNA polymorphism in the Udmurt population, which represents a Finno-Ugric ethnos residing in the Volga-Ural region. Our analysis of the Udmurt mtDNA polymorphisms have shown that neighboring ethnoses had almost no effecton formation of the Udmurtian intraethnic diversity. These results strongly indicate that genetic differences in the Udmurtian population are determined by their tribal structure rather than their geographic location.