Introduction: In recent years, the frequency of human immunodeficiency virus (HIV) and hepatitis C (HCV) co-infection has increased, which is due to their common routes of transmission. HIV/chronic HCV co-infection aggravates the development of fibrosis and increases the risk of cirrhosis. The aim of the study was to evaluate the results of liver elastometry in patients of different ethnic groups with HIV/chronic HCV co-infection. Methodology: The study involved 49 Kazakh and 46 Russian patients with HIV/chronic HCV co-infection. The stage of liver fibrosis was assessed by the results of indirect ultrasonic liver elastometry according to the METAVIR scale using FibroScan 502. As an indirect marker of liver fibrosis, level of alanine aminotransferase and aspartate aminotransferase, as well as platelet counts, were determined. Results: Analysis of the results with the evaluation of the dynamics of fibrotic process in 36 months revealed a prevalence of patients with advanced liver fibrosis (F3, F4) among Kazakh compared with Russian patients, accompanied by a significant increase of liver elasticity indices in Kazakhs and Russians (p < 0.05). Significant differences in the indices of transaminases in the patients with later stages of liver fibrosis (F3, F4) were found (p < 0.05). Conclusions: The study of patients with HIV/chronic HCV co-infection revealed differences in the progression of liver fibrosis depending on ethnicity. Results of elastometry and indirect markers of liver fibrosis were used in the comprehensive assessment at different stages of liver fibrosis.