Objective — to comparatively study the indicators characterizing the major risk factors of cardiovascular diseases (CVD) in thyroid hypofunction in the populations of the Russian Federation (RF) and the USA. Material and methods. The association of thyroid hypofunction with cardiovascular risk factors was studied through a secondary analysis of the data of cross-sectional population studies of the RF (Epidemiology of CVD diseases and their risk factors in different RF regions (ESSE-RF)) and the USA (Continuous National Health Nutrition Examination Survey (Continuous NHANES, 1999—2012)). Nonparametric statistical methods were used. Thyroid function was evaluated from the blood concentration of thyroid-stimulating hormone. Results. Among the adult populations, the proportion of patients with hypothyroidism was 3.5% in the RF and 3.8% in the USA (the difference were insignificant). The persons with this condition versus those in the control groups showed no significant differences in blood pressure. In hypothyroidism, the body mass index was high, as shown by the ESSE-RF data; the U.S. population studies demonstrated an upward trend for this indicator. The hypothyroidism group showed regular changes in the lipid profile; the most important characteristic was elevated triglyceride concentrations. Conclusion. Among the RF and U.S. adult populations, the proportion of patients with hypothyroidism does not significantly differ and accounts for 3.2-4.4%. In hypothyroidism, there are changes in the number of indicators at the population level, which are poor in terms of the profile of risk factors for atherosclerosis, besides they often appear just in subclinical hypothyroidism.