The peculiarities of the microbiocenosis of the uterine cavity in 184 patients of reproductive age with different types of endometrial hyperproliferative processes were studied: Group 1, n=60, non-atypical endometrial hyperplasia (NAEH); Group 2, n=62, endometrial polyps (EPs); Group 3, n=62, NAEH + EPs. Correlation analysis of the degree of association between different biological media (uterus and genital tract) was carried out. Contamination of the uterine cavity by bacterial flora was diagnosed in all groups of patients examined. Anaerobic flora was about 30% while bacteria of the genus Bacteroides were the most common. Among aerobic organisms, representatives of the Enterobacteriaceae family and coccal flora are noted. The widest was the spectrum of isolated microorganisms in patients of group 2 (with endometrial polyps). A strong positive correlation was established between indices of genital tract contamination and the uterine cavity by coccal flora, Escherichia coli, and anaerobic organisms. The findings suggest dysbiotic changes and the presence of a chronic inflammatory focus in the endometrium, which pathogenetically substantiates the application of anti-inflammatory therapy in such patients.