Androgenetic alopecia in the female occurs much more frequently than is generally believed. The condition is still considered infrequent, for it differs, in its clinical picture and in the sequence of events leading to it, from common baldness in men. To facilitate an early diagnosis (desirable in view of the therapeutic possibilities by means of antiandrogens) a classification of the stages of the common form (female type) of androgenetic alopecia in women is presented. The exceptionally observed male type of androgenetic alopecia can be classified according to Hamilton or to the modification of this classification proposed by Ebling & Rook.