Objective — to study and analyze local humoral and cellular protection changes in women with endometriosis of the cervix uteri. Subject and methods. A study group consisted of 56 patients with endometriosis of the cervix uteri. A control group included 30 apparently healthy women. Liquid-based cytological examination of biopsy specimens from the vaginal portion of the cervix uteri and cervical canal was performed to determine the total levels of cells and a total cytogram and to calculate the relative amounts of different cell elements (squamous, intermediate, cylindrical, and basal epitheliocytes, eosinophils, neutrophils, lymphocytes, monocytes, and macrophages), their ratio indices (leukocyte-epithelial and epithelial regeneration indices, epithelial metaplasia index), and phagocytic indicators (phagocytic index, phagocyte number). To assess local humoral immunity, the cervical mucus levels of the secretory component of immunoglobulins A, G, and M, and lysozyme were estimated by the simple separate gel immunodiffusion assay developed by G. Manchini. Results. In patients with external genital endometriosis of the cervix uteri, the local protective system manifests itself as a moderate rise in the total levels of cells, as well as local leukocytosis, a reduction in epithelial regeneration index, increases in leukocyte-epithelial and epithelial metaplasia indices and phagocytic indicators, and decreases in immunoglobulins and lysozyme in the cervical mucus. The limits of the examined indicators were used to develop their reference values and criteria for diagnosing impairments in the local protective system. Conclusion. The accessibility and simplicity of the study permit its wide clinical application to diagnose and substantiate pathogenic therapy. The authors declare no conflicts of interest.