Introduction. The HIV epidemic situation in the Russian Federation remains tense. Low coverage of antiretroviral therapy (ART) contributes to the disease progression in some PLHIV. Many authors point to a high prevalence of different secondary disease combinations. Objective. Studying the structure of secondary disease combinations in inpatients and identifying features of immunological and virological indicators. Materials and methods. There was retrospective analysis of 1440 cases of HIV-infected admission in ICU SBHI «ICH № 2» DZM in 2018–2020. The number of CD4+ cells were estimated in 1185 patients, viral load (VL) is defined in 1173 patients. Statistical analysis is held, using program StatTech v. 2.6.2 (developer — LLC «Statech», Russia). Results. 18,5% of patients had 1 secondary disease, 75,9% were diagnosed a combination of 2 and more various lesions. 275 different combinations of secondary diseases are recorded: from 50 combinations of 2 secondary lesions to 4 combinations of 7 nosological units. Ме VL in patients with no secondary diseases — 13 303 copies/ml, with 1 secondary disease it increased 3,2 times (42 926) (p<0,001). Similar changes are detected with 3, 5 and 6 diseases. Ме number of CD4+ lymphosytes in the absence of a secondary pathology — 223 cells/mcl. As the number of secondary diseases increases from 1 to 4, we observe consistent reduction in the number of CD4+ lymphosytes; in a combined secondary pathology Ме CD4+ cells did not exceed 100 cells; with 4 and more secondary diseases this figure did not exceed 20 cells in mcl. Correlation analysis of CD4+ cells and the number of combined secondary diseases revealed the presence of moderate connection tightness on the Chaddock scale (rxy=0,356, p<0,001). The depth of immunodeficiency also affects the outcome of the disease: (M±SD) CD4+ cells in the group of the dead were 101±153 (95% DI: 91–112), in the group of survivors — 198±226 (95% DI:172–224; p<0,001). Conclusion. Combined secondary disease among patients of ICU infectious hospital were diagnosed in 75.9% patients. There were differences by VL level which increased with the growth of combined lesion number; more significant correlation was found between the amount of CD4+ cells and the number of secondary diseases. The obtained results are confirmed by reduced likelihood of a favorable outcome of the disease with increasing number of combined secondary diseases. © 2022,HIV Infection and Immunosuppressive Disorders. All Rights Reserved.