Amenorrhea is absence of menses in a young girl till a particular age or in a woman of reproductive age for a definite period. This is categorized into two types following as primary and secondary amenorrhea. This chapter covers the physiology of menstruation, classification of amenorrhea (according to etiology list of conditions), evaluation of amenorrhea, history and examination, investigations for primary and secondary amenorrhea, evaluation of specific conditions in amenorrhea, management of amenorrhea, management of end organ disorders, management of gonadal agenesis and dysgenesis, management of premature ovarian failure, and management of hypogonadotropic hypogonadism. The key to management of women with amenorrhea is to make a correct diagnosis especially in young girls where primary amenorrhea is a very emotionally draining concern, not only for the girl but also for the family and counseling is an integral part of management of all such cases.