Anti-Müllerian hormone (AMH) is a glycoprotein produced by the granulosa cells of preantral and small antral follicles. AMH concentrations reflect ovarian physiology with high precision, thus serving as a more sensitive marker of the ovarian reserve than the chronological age. This hormone plays a role in the pathogenesis of menstrual disorders and fertility in obesity and polycystic ovary syndrome. The evaluation of AMH may also be useful in the diagnosis or the monitoring therapy of granulosa cells ovarian tumors.