Endometriosis is one of the most common diseases in reproductive-aged women: the incidence ranges from 5 to 10% of all the diseases of the female reproductive system. With the rising incidence of different forms of endometriosis, the development of endometriosis-associated infertility and persistent pain syndrome becomes more pronounced. Objective — to identify the risk factors associated with the development of endometrioid ovarian cysts and/or deep infiltrating endometriosis in Russian women. Subject and methods. The international case-control study was conducted from May 2011 to April 2013 in 18—41-year-old patients, in whom the diagnosis of endometriosis was confirmed during surgery (laparoscopy or laparotomy) for benign gynecological disease in the last 3 months. The international study enrolled a total of 1008 patients, including 308 patients from Russia, 307 of whom were included in the analysis under this protocol. This study enrolled 219 (71.3%) patients with endometriosis. 88 patients of them had superficial peritoneal endometriosis (PE), 88 had endometrioid ovarian cysts, and 43 had deep infiltrating endometriosis. A control group consisted of 88 (28.7%) women without endometriosis. After surgery, all the patients filled out a questionnaire for the assessment of environmental (sun exposure) and lifestyle (dietary preferences, bad habits) factors as risk factors for the development of endometriosis. Results. There were no significant differences between the patient groups in terms of indicators, such as height, weight, body mass index or age at menarche. The incidence of endometriosis was 2.3% in the close relatives of women in the control group and 11.4—18.6% in those of women with endometriosis. The patients with endometrioid ovarian cysts and deep infiltrating endometriosis were more frequently found to have pelvic pain unassociated with menses and more severe dysmenorrhea (> 60% of cases) (assessment using a visual analog scale — VAS) compared with these clinical manifestations in those in the control or superficial endometriosis groups. The severity of algodysmenorrhea averaged 8.3 cm on the VAS in women with deep infiltrating endometriosis. The women with endometriosis more often complained of painful ovulation that was noted in 35.2, 42, and 55.8% of the patients with superficial endometriosis, endometrioid ovarian cysts, and deep infiltrating endometriosis, respectively; compared with that in the control group (30.7%). Dyspareunia was more common in the patients with endometrioid ovarian cysts and deep infiltrating endometriosis (52.3 and 72.1%, respectively) than in the women without endometriosis (28.4%). Menstrual pain affected not only the professional and social life of women, but also their sexual life in 67.3% of the women with endometrioid ovarian cysts and in 86.2% of those with deep infiltrating endometriosis. The patients with external genital endometriosis were more frequently observed to have primary rather than secondary infertility. Lifestyle (dietary choices, bad habits (smoking, alcohol consumption)) and environmental (sun exposure) factors were not ascertained to affect the development of endometriosis. Conclusion. The analysis of the data obtained in the international study of the population of Russian women has shown that lifestyle and environmental factors have no impact on the development of endometriosis. Algodysmenorrhea and dyspareunia are of great importance to diagnose deep infiltrating endometriosis and endometrioid ovarian cysts in the early stages.