Objective. To evaluate the effectiveness of using didrogesterone in combined therapy of endometriosis-associated. Patients and methods. The study included patients with infertility and verified diagnosis of ovarian endometriosis. The screening involved 108 women, of them 75 corresponded to the inclusion criteria. They were divided into two statistically comparable groups depending on a therapy option aimed at management of infertility. Group 1 (n = 36) included patients who underwent only surgical treatment, group 2 (n = 39) – women, who received combined therapy (surgical treatment + didrogesterone 10 mg/day from the 14th to the 25th day of the menstrual cycle for 6 months). The effectiveness of treatment was assessed by the incidence of clinical pregnancy within a 12-month follow-up period and, in case of pregnancy occurrence, by its outcomes. Results. As has been found, pregnancy incidence in women who received combined therapy exceeds by 1.6 times the results in the group of patients who underwent only surgical: 69.2 vs. 44.4%, p = 0.03. In combined treatment with the use of didrogesterone in the second phase of the cycle, the percentage of live births from the total number of pregnancies was significantly higher (by 1.3 times) as compared with group 1, and taking into consideration a greater incidence of pregnancy, the chances of successful management of infertility were by 2.4 times higher with inclusion of didrogesterone in therapy: 59.0% (23 of 39) in group 2 and only 25.0% (9 of 36) in group 1 (p = 0.0029). Conclusion. The use of didrogesterone as post-operative therapy and pregravid preparation of patients with endometriosis-associated infertility significantly improves the effectiveness of treatment and reproductive outcomes. © 2020, Dynasty Publishing House. All rights reserved.