This is a short monograph on the classification, investigation, and treatment of amenorrhea of primary and secondary origin. Unfortunately, some confusion is caused by the citation of many authorities without an attempt to organize or draw conclusions from their material. However, this criticism, if it can be called that, does not extend to the excellent review of the Russian investigations and the section on therapy. In the latter, the roles of the estrogens, thyroid, gonadotropins, progesterone, and combined hormonal therapy are briefly reviewed by abstracts of the literature. Less frequently utilized forms of therapy, such as roentgen ray techniques and neostigmine, are also included.