1. Six hundred colorimetric determinations of androgens and estrogens were performed on the urines of 200 individuals.2. A standard curve for the daily excretion of androgens and a norm for the ratio male: female hormones was established.3. Of 29 overt homosexuals 25 show a very characteristic staircase sign, namely, male hormones relatively lower and an excess of estrogens.4. Other sexual abnormalities, especially transvestism, do not show this staircase sign.5. Of 12 patients with impotence, 8 cases on a neurotic basis show a very low excretion of androgens and estrogens; the remaining 4 cases show special problems.6. Another characteristic finding appears in masturbators in whom 6 out of 7 patients show a very high excretion, both in androgens and estrogens.7. In castration and eunuchism excretion is low; in a case of eunuchism of 25 years' duration, half of the amount of excreted androgens was present in the form of androsterone.8. In certain endocrine conditions, sex hormone findings appear consistently: high excretion in adrenal tumors; low excretion in pituitary disease; and severe damage to the genital and extra-genital sites of formation of male sex hormones in chronic cases of hypo and hyperthyroidism. In other endocrine conditions, such as in the undescended testicle and hirsutism, the findings are not uniform.9. Various neurological diseases, such as epidemic encephalitis, Simmond's cachexia, diabetes insipidus and sclerodermia show a diminution of hormones which demands further study.10. Our findings in the major psychoses are still incomplete. There is no pathogenetic relationship between hormone excretion and involutional melancholia.11. In children there is a gradual increase of androgens and estrogens according to age and general physical development, reaching in puberty a level even higher than that in the middle-aged adult. There is, however, no evidence of active sexual hormones in very young children, and there is nothing in their urine which can be compared to the typical findings in homosexuality or other types of sexual disturbance.12. Ultraviolet irradiation is a physiological method of restoring a disturbed hormone balance and, therefore, may play a role in treatment of certain neuropsychiatric conditions.