Objective:To analyze the effect of preoperative preparation on vaginal architectonics and vaginal microbiota composition in women with stage III, IV genital prolapse POP-Q in combination with genitourinary menopausal syndrome. Methods: A prospective randomized trial was conducted on the basis of the gynecological department of the Federal State Budgetary Institution of Research Institute of OMM of the Ministry of Health of Russia in the period 2018-2020. The study included 100 women aged 52 to 79 years with prolapse of the anterior vaginal wall of stage III, IV according to POP -Q. The first group are women who were given local hormone therapy (estriol and progesterone) in combination with lactobacteria at the preoperative stage (n = 35); the second group -local monotherapy with estriol (n = 35), the third group (control) -without previous preparation for surgery (n = 30). Material for morphological and immunohistochemical examination -biopsy of anterior vaginal wall mucosa was obtained during surgery. To determine the state of the receptor apparatus of the vaginal mucosa (ERα, ERβ), an immunohistochemical study was carried out. Real-time diagnosis based on polymeresis chain reaction was used to determine vaginal microbiocenosis.Results: It has been found that the use of vaginal forms of estrogen and progesterone in combination with lactobacteria reduces the intensity of the inflammatory process in the vaginal mucosa, reduces the severity of dystrophic changes, and also statistically significantly increases the level of ERα expression and ERβ in all layers of the vaginal epithelium. Comparative characterization of Candida spp. after treatment, the observation groups showed a significantly lower number of yeast-like fungi in the first group with a statistically significant increase in lactobacillary flora. Conclusion:This study revealed a significant positive effect of preoperative vaginal preparation using complex therapy with estriol, progesterone in combination with Lactobacillus on architectonics, local vaginal immunity and vaginal microbiota in women with severe postmenopausal genital prolapse.Recommendations: As a local preoperative preparation of the vaginal mucosa, it is recommended to give preference to a complex approach -the use of local forms of estriol and progesterone in combination with lactobacteria.