Data are presented on the urinary excretion of androst-16-en-3\g=a\-olby normal human subjects over the age span 4-86 years. The figures range from < 100 to 2630 \g=m\g./24 hr. in males, and < 100 to 1100 \g=m\g./24 hr. in females, the mean for men of 16-45 years being nearly three times that for women of the same age.The effect on urinary androstenol and 17-oxosteroids of human chorionic gonadotrophin (HCG) and of corticotrophin (ACTH) have been compared in three normal young men and two women. Marked elevation of androstenol excretion occurred after ACTH in both sexes, while HCG administration resulted in an increased urinary output of androstenol and 17-oxosteroids only in two of the men and not in the women tested in either phase of the menstrual cycle. Intramuscular injection of androstenol itself (20 mg.) resulted in increased levels of androstenol in the urine equivalent only to a very small proportion of the injected dose.The metabolic origin of androstenol is discussed in the light of the results presented and of those of other investigators. It seems likely that androstenol arises not primarily from testosterone but mainly from an adrenal precursor.