Anti-Müllerian hormone (AMH) is a homodimeric glycoprotein, a member of the transforming growth factor-β superfamily. Over the last decade, a large number of studies examining the multiple roles of AMH have been published. AMH levels accurately reflect the ovarian follicular reserve and could, therefore, be considered as an extremely sensitive marker of ovarian aging and a valuable tool in the diagnosis and the recognition of recurrence of granulosa cell tumors. Furthermore, AMH evaluation is of clinical importance in predicting the success of in vitro fertilization (IVF). Additionally, AMH could be a surrogate diagnostic marker of polycystic ovary syndrome in cases in which ultrasonographic examination is not possible. This article is a review of the clinical usefulness of AMH evaluation in the fields of gynecological endocrinology, menopause, gynecological oncology and assisted reproduction. Special reference is made to the possible implications of AMH in the pathogenesis of polycystic ovary syndrome and the relationship between AMH and obesity.