The genetic markers (encoding factor of blood coagulation, the PAI-1 gene, the prothrombin gene, the GP IIb/IIIa gene, and the MTHFR gene) of thrombosis were studied in the Mordovians and Russians with essential hypertension (EH), who were residents of the Republic of Mordovia. One hundred and forty patients with TH and 90 healthy individuals of three nationalities, such as Russian, Moksha-Mordovian, and Erzya-Mordovian, were examined. Along with the routine clinical and instrumental studies, alleles of polymorphic markers were identified by the polymerase chain reaction (PCR). The polymorphic markers of the Arg 506 Gln gene, encoding factor V of blood coagulation, 4G5G of the PAI-1 gene, the G 20210 A prothrombin gene, the GP IIb/IIIa gene, and the A 1298 C MTHFR gene were also studied. The data were statistically analyzed using a package of the programs: Statistica for Windows 6.0 (Stat Soft), SPSS (version 14.0), and MS Excel XP (Microsoft). The authors used a chi-2 (chi-square) test was used to compare the incidence of genotypes and alleles in the patient groups. Hypertensive and normotensive persons were found to have no significant differences in the distribution of genotypes (encoding factor of blood coagulation, the PAI-1 gene, the prothrombin gene, and the GP IIb/IIIa gene) with regard to ethnicity in the Russian, and Moksha-Mordovian, and Erzya-Mordovian groups). Meanwhile, there was a significant preponderance of MTHFR gene mutation with the unfavorable genotype for Moksha-Mordovian patients with EH. The findings suggest that drug therapy for preventing venous thrombosis in patients with EH should be adjusted in relation to ethnicity.