Premature menopause is characterized by amenorrhea, elevated circulating gonadotropin levels, and low circulating estrogen levels in women under the age of 40 years. Although hormonal values are similar to those found during the menopausal transition and after menopause, it is clear that women with this disorder differ in important ways from normal postmenopausal women. The use of the term premature menopause itself is inappropriate because approximately half have eveidene of ovarian function and 6% to 8% will ovulate after the diagnosis is made. This article focuses on what is known about several distinct mechanisms for the ovarian failure and conclusions by briefly offering potential treatment strategies.