Objective — the purpose of the study was the clinical and morphological investigation of neurogenic mechanisms of the pathogenesis of pain syndrome in endometriosis. Material and methods. The study was performed on the surgical material (sections of resected bowel, bladder, rectovaginal septum, pelvic peritoneum) obtained from 52 women diagnosed with endometriosis, with pain (I group) and without pain (II group). Pain intensity was assessed with scores (0 to 10), as described in subjective assessment of pain — Visual Analogue Scale (VAS). We used the Beck Scale, Spielberger—Hanin, and SAM tests and questionnaires to assess the psycho-emotional state of patients, and the SF-36 questionnaire to assess their quality of life. The immunohistochemical study was performed on paraffin sections, according to the standard protocol with use of antibodies: 1) polyclonal rabbit to PGP 9.5; 2) mouse monoclonal to human neurofilament protein (NF); 3) monoclonal mouse to NGF; 4) murine monoclonal to Neurotrophin receptors (NGFRp-75) («Dako», Denmark). Results. Our results show that the painful form of the EGE differs from the painless form, the former having a more severe course of disease. We have obtained high expressions of PGP 9.5, NF, NGF and NGFRp75 in endometriotic lesions and the surrounding tissue in the painful form of EGE, regardless of the localization of heterotopias. Conclusion. Thus, based on the conducted study, it can be concluded that the psycho-emotional state of women with EGE combined with pain syndrome, and the degree of pain are associated with the presence of high expression of PGP 9.5, NF, NGF and its receptor NGFRp75 in the foci of endometriosis and the surrounding tissue.