Seventy amenoroic, thirty oligomenoroic and twenty-four polymenoroic patients with hyperprolactinemia were observed. Anovulatory cycles: A statistically significant fall of the mean concentrations of gonadotropins and estradiol was not noted in any symptomatic group with the increase of the prolactin values. The mean values of gonadotrophins and estradiol were characteristic of hypogonadotropic hypogonadism when the concentration of prolactin was higher than 4000 mIU/l. The relations of gonadotrophins were changed and the value of FSH was significantly lower than LH when prolactin was up to 4000 mIU/l. The mean values of gonadotrophins did not differ significantly in amenoroic, oligomenoroic, and polymenoroic women belonging to the same group according to the prolactin concentrations. A significant difference however, was noted in the estradiol mean values. - Ovulatory cycles: Women belonging to the same group according to the prolactin concentrations did not differ significantly in the probability of ovulation, regardless of whether their cycle was amenoroic, oligomenoroic or polymenoroic. The probability of ovulation decreases significantly when prolactin values are higher than 2000 mIU/l.