Aim. To evaluate the efficacy of boosted darunavir and atazanavir used in antiretroviral therapy (ARVT) regimens for treatment-naïve HIV-infected patients with low baseline immune parameters and a high viral load. Materials and methods. The investigators evaluated the clinical, immunological, and virological efficiency of treatment: the time course of changes in CD4+ lymphocyte levels and viral load at the beginning and at 12, 24, 48, 72, and 96 weeks of antiviral therapy, as well as adverse reactions. Results. The virological effect of once daily darunavir/ritonavir 800/100 mg was highly competitive with that of atazanavir/ritonavir: at 96 weeks of treatment, HIV RNA <120 copies/ml was achieved in 95% of the patients in both treatment groups. A combination of once daily darunavir/ritonavir 800/100 mg ensured a more marked immunological improvement: a difference in the increment (77.1 in 1 µl) of CD4+ lymphocyte count in patients who took darunavir (362.2 in µl) and in those who used atazanavir (285.1 in µl). In the patients who received darunavir, diarrhea, nausea, and headache were observed at the same frequency as in those who had atazanavir. Conclusion. The use of the test agents used in the ARVT has shown their efficacy and good tolerability.