Sexually-transmitted infections are among the most well-known risk factors for HIV infection. The problem of combined diseases of STIs and HIV in infected people is represented by few works in the domestic scientific literature, therefore further study of this issue is required. Objective: to identify the prevalence of sexually transmitted infections in HIV-infected patients at the time of registration. Materials and methods. 49 clinical histories of patients with HIV infection were analyzed and studied at the Republican Center for the Prevention and Control of AIDS and Infectious Diseases of the Ministry of Health of the Republic of Tatarstan. Results. STIs with the prevalence of urogenital chlamydia, ureaplasmosis and mycoplasmosis in the oligosymptomatic clinical course were registered in 63% of patients (predominantly women — 67% of cases) with HIV infection in the natural infectious process course. Patients with HIV infection and syphilis showed lower level of CD4 lymphocytes and high levels of HIV RNA viral load.