More than 40% of patients, who were newly diagnosed HIV infection in Russian Federation in 2014, had pronounced immunodeficiency. Timely diagnosis of the diseases of the skin and mucous membranes, which are indicative of immunosuppression, facilitates detection and identification of HIV infection stage in patients. Objective — the research was aimed at studying manifestations of hairy leukoplakia (HL) in HIV infected individuals, assessing the level of HIV RNA in the blood plasma (BH), the absolute number of CD4+ T-lymphocytes, and their percentage in patients with HL, and developing an algorithm of HL diagnosis. Material and methods. The retrospective study included 200 HIV-infected individuals, who did not receive antiretroviral therapy (ART). The patients were divided into two equal groups: group 1 included HL patients, group 2 included individuals without HL. We compared BH level, the absolute number and percentage of CD4+ at the moment of HL diagnosis (measured within 120 days before or after the date of HL diagnosis). Results. In 94% of cases, HL involved both sides of the tongue, one-sided localization was observed in 6% of cases. CD4+ T-lymphocyte count below 200 cells/μl was significantly more frequent in HL patients (62%), more than 350 cells/μl — in the control group (46%). Less than 14% of CD4+ was found in 65% of HL patients (31% in group 2). BH level of more than 100 thousand copies/ml was more common in patients with HL (60%); in group 2 — 31%. At the same time, less than 200 CD4+ T-lymphocytes/μl, their proportion lower than 14%, and BH of no less than 100 thousand copies/mL was detected in 45% of Group 1 patients and 15% of group 2 patients. Conclusion. In HIV-infected individuals, HL can be considered as a reliable clinical marker of severe immunosuppression (CD4+ below 350 cells/μl and their percentage below 14%) and/or high plasma level of HIV RNA.