Background: Several IRMA and enzeme-linked immunosorbent assay (ELISA) kits used to determine PRL are available. In practice, most routine PRL determinations are performed on automated immunoassay systems with either chemiluminescence or fluorescence-based detection. PRL usually is calibrated against references materials with WHO reference materials. Without the performance of such calibration PRL results that are expressed in mass units are not comparable from assay to assay. Hyperprolactinemia is present in 15% to 20% of women undergoing evaluation for infertility .In some studies the severity of hyperprolactinemia roughly correlates with the degree of menstrual dysfunction. In an infertility clinic in Brazil, Bahamondes and colleagues (1985) reported hyperprolactinemia in 55% of women with amenorrhea, in 37% with oiigomenorrhea, and in 9% with normal menses. Galactorrhea occurs in 50% to 80% of women with. hyperprolactinemia and may occur with or without menstrual dysfunction . The regulation of prolactin secretion is mediated through the inhibitory effects of hypothalamic dopamine. In animals and humans hypersecretion of prolactin leads to inhibition of gonadotropin-releasing hormone (GnRH) secretion. Although the primary abnormality in  hyperprolactinemia is a decrease in hypothalamic GnRH secretion, prolactin also has a direct inhibitory effect on the ovaries, leading to decreased estrogen synthesis. Objectives: To study the incidence of hyperprolactinemia in infertile females in Egypt. Methods: two groups participated in this study group I composed of 36 subjects with hyperprolactinemia and the other Group II composed from 36 healthy women as a control group . PRL-TSH and FT4 hormones were analysed in two groups by chemiluminescence immunoassay (cobas) .Results: Significant higher value of (PRL) and (TSH) (p< 0.001) were observed in the patient group (I) when compared with control group II. While significant lower values (p < 0.001) in F-T4 were observed in patients of group I.when compared with control group II. Conclusions: there is a high incidence of hyperprolactinaemia in 1ry infertile women mainly with galactorrhea and there is a good positive correlation between hypothyroidism and hyperprolactinemia .