Endometriosis is one of the most relevant problems in modern gynecology. This pathology often leads not only to structural and functional changes in the reproductive system and cause infertility (35-50 %), but also generally significantly worsens physical health, the work capacity and can affect the psycho-emotional state of women. As endometriosis is diagnosed in almost every third of women and there is a trend for its rate increase, it remains a subject of special interest not only for scientists, but also for practical doctors. Despite of a lot of literature data, currently, there is no protocol, international guideline, which provides uniform algorithms for the diagnosis and treatment of endometriosis with subsequent realization of reproductive function. The experts pay attention to an individual approach for the comprehensive solution of the problem regarding the age of the woman, the localization and extent of the process, the severity of symptoms, the state of fertility and the necessity to restore reproductive function, the presence of concomitant gynecological and somatic pathology, and the effectiveness of previous treatment. The article provides a clinical description of a case of spontaneous pregnancy with bilateral endometriosis of the ovaries, which was diagnosed before pregnancy, with favorable maternal and fetal outcomes. An ultrasound description of endometrioid changes in the pelvic organs during the pregnancy is presented. The authors developed an individual management plan for the patient in accordance with her young age, high ovarian reserve, which in the presence of patency of the fallopian tubes and normal indicators of the man’s spermogram can be considered as prognostic factors for evaluating the appropriate reaction of the ovaries in case of spontaneous conception. During the operative delivery (caesarean section), the surgical treatment of endometriosis of the ovaries was performed at the same time. The patient and the newborn were discharged from the hospital under the supervision of a gynecologist in a satisfactory condition.