Hyperprolactinemia is the most common hypothalamic-pituitary axial disorder which is found in clinical practice. Increased level of prolactin, regardless of the cause, results in disorder of gonadal function and infertility, while normalization of the level of prolactin is associated with establishment of normal gonadal function and fertility. Establishment of the correct diagnosis is a great significance, because it is possible to normalize the level of prolactin and establish normal function of ovaries in more than 90% cases with specific therapy. The objective of the work is to study concentration of prolactin in each phase of menstrual cycle, its impact (influence) on FSH, LH and E2, as well as the influence of hyperprolactinemia on the rhythm of menstrual cycle. The study has encompassed 150 of women in reproductive period, from 18-40 years of age. The control group includes 50 of women, and there are 100 of women with menstrual cycle disorders (oligomenorrhea, polymenorrhea and secondary amenorrhea) which causes hyperprolactinemia. The turnout of hyperprolactinemia in causes the disorders of menstrual cycle (oligomenorrhea, polymenorrhea, amenorrhea) is 83%, on the basis of the results, wich demonstrates a serious problem and justifies a scientific study.