The familial incidence and distribution of hirsutism and other related symptoms have been ascertained in 90 females ranging in age from 15 to 45, in their first degree relatives (mothers and sisters), and in a control group. On clinical grounds, patients were placed in 3 categories: ovarian, adrenal and “idiopathic” hirsutism. A method was elaborated for semiquantitative estimation of the occurrence of “unusual” body hair for women and of symptoms of endocrine dysfunction. The pattern of distribution of hirsutism resembles that of a continuous one, suggesting a gradient trait ranging from the normal female to the abnormally hirsute. A significant familial aggregation of hirsutism was found and propositi with their relatives constituted a different population than controls in regard to hirsutism. This result along with the intermediacy of scores in relatives set the basis for a genetic etiology, a multifactorial pattern of inheritance being a plausible one. In hirsute women an association with varying degrees of endocrine dysfunction was constantly observed. The distribution of the scores for endocrine symptoms was parallel to that of hirsutism.