Aim. Is specification of the nature and frequency of concomitant forms of genital endometriosis and other estrogen-dependent diseases (EDD) for the infertile women with severe peritoneal endometriosis (PE), as well as the assessment of the ovarian reserve condition for the patients of different ages. Materials and methods. The total 142 infertile women with severe peritoneal endometriosis (III-IV stage of the external genital endometriosis according to the American Fertility Society classification) were examined at the age of 32.3±3.2 years (min-max = 23-40 years). The clinical status assessment was conducted, using a standard set of diagnostic procedures, prescribed for the inclusion of patients in the IVF program. The ovarian reserve was estimated by the level of the anti-Mullerian Hormone level determined by the immunoenzyme method. Results. The concomitant 2-sided endometriotic ovarian cysts (96%), myoma (19.7%) and the adenomyosis (16.9%) were most common for the patients with severe peritoneal endometriosis. The severely reduced the anti-Mullerian Hormone rates (<0.4 ng/ml) were much higher among patients >35 years old (24.6% compared to 10.6% for younger patients; p=0.028). Conclusion. The infertility for severe peritoneal endometriosis is supported by concomitant estrogen-dependent diseases, of which 2-sided endometriomas, adenomyosis and uterine myoma are of the most pathological. The low efficiency of IVF in the treatment of patients with severe peritoneal endometriosis and concomitant estrogen-dependent diseases is explained by the aggravation of the embryonic and endometrial factors for the infertility. The other reason that worsens the results of IVF for such patients is late reproductive age (>35 years) that increases the observed reduction of the ovarian reserve. © 2021 Consilium Medikum. All right reserved.