Introduction: Endometriosis is defined as the appearance of ectopic endometrial cells outside the uterine cavity. Ectopic cells demonstrate functional similarity to eutopic cells, but structural and molecular differences are significant and manifest themselves in gene expression of the metalloproteinase genes, integrin or the Bcl-2 gene. Pelvic pain remains to be the main symptom of the disease. Endometriosis may cause dysfunction of the reproductive system and lead to infertility. Pathogenesis of infertility in endometriosis is based on its influence on the hormonal, biochemical and immunological changes in the eutopic endometrium, as well as structural damages of the ovaries and the fallopian tubes. Objectives: The aim of the study was to assess the ovarian reserve in patients with endometriosis. Material and methods: A total of 39 patients (aged 22-34 years) with different stages of endometrial changes were recruited for the study. The number of antral follicles was rated by vaginal ultrasonography and the level of FSH was measured between days 1-3 of the menstrual cycle. The stage of the disease was established after laparoscopy with the rASRM scale. Results:No statistically significant correlation between the number of follicles(AFC), the level of FSH and the stage of endometriosis was found. Conclusions: Evaluation of the number of antral follicles and measurements of the FSH level do not allow to predict the ovarian reserve in women with endometriosis.