Background. Benign prostatic hyperplasia (BPH) is a histologically determined condition of the male body and is characterized by glandular-stromal multi-focal proliferation originating from the paraurethral and (or) transition zone of the prostate gland. Proliferative processes in the body are under the control of the immune system. Identifying and understanding the immunological aspects of prostatic hyperplasia can help control prostate tissue growth, improving men's quality of life. The aim of our study was to conduct a pilot study, assessment of the immune status of patients with benign prostatic hyperplasia. Materials and methods. The study included patients having stage 2 BPH (according to Guyon’s updated classification system (n=8)) and patients who did not have clinical and morphological manifestations of BPH. The subjects underwent standard examinations in accordance with the clinical protocol of the Ministry of Health of the Republic of Belarus. The immunogram indicators included: the main subpopulations of lymphocytes (CD3 T lymphocytes, CD4 T helper cells, CD8 T cytotoxic lymphocytes), the ratio of Th/Tc, CD19 B lymphocytes, the level of serum immunoglobulins IgG, IgM, IgA and circulating immunocomplexes (CIC), as well as phagocytic index and phagocytic number. Results. Patients with BPH had statistically lower levels in the number of phagocytosed units compared to the patients without BPH. Furthermore, patients with BPH have highly variable results for immune system indices. Thus, the ratio of Th/Tc ranged from 1,3 to 2,3 units, and the level of CIC – from 10 to more than 300 units. The variability of the results obtained allowed us to divide patients with BPH into two groups: first group (n=3) with normal indices for levels of CIC and for the ratio of Th/Tc; the second group (n=5) with the indices for levels of CIC and for the ratio of Th/Tc that significantly exceeded the reference values. None of the patients in the second group had a concomitant autoimmune disease. Conclusions. Patients with BPH have a dysfunction of the immune system. Even having such a small number of enrolled subjects, it is possible to form subtypes of patients with BPH – they are future phenotypes. The study aiming at finding immunological disorders in patients with benign prostatic hyperplasia should be continued.