Five years ago, while I was resident at the Research and Educational Hospital of the University of Illinois, a woman with Fröhlich's syndrome was treated with various pituitary preparations. During the treatment, she developed a luxuriant hair growth, in addition to regaining her normal sexual desires, reestablishing her menstrual cycle, and losing weight. The growth of hair was particularly remarkable in that the patient and her immediate female relatives (mother and two sisters) all had, since early youth, a scanty atrophic type of hair, prone to dryness and easy end-splitting. Inferring a relationship of the pituitary therapy to this patient's hair growth and its change in texture, I began to study the effects of certain pituitary preparations in cases of alopecia and I am now in position to report on sixteen patients, in all of whom the results were so striking that a preliminary report seems desirable to render this