Ethinyl estradiol was administered orally to a group of 33 meno-pausal 22- The dosage varied from 0.05 to 0.15 mg., given one to 3 times daily. Excellent control of symptoms occurred in 27 cases, moderate control in 2 cases, and in only 4 cases was the drug ineffective. Vaginal smears and endometrial biopsies in most of the cases showed changes compatible with estrogenic activity after variable periods of therapy. Vaginal bleeding during therapy appeared in 7 cases; withdrawal bleeding occurred on cessation of therapy in one case. During treatment 3 patients complained of headaches; in one it was sufficiently severe to necessitate discontinuing treatment, in the other two the headaches disappeared. Nausea and vomiting did not occur. This new oral steroid estrogen, ethinyl estradiol, has shown great effectiveness in controlling the symptoms of the menopause. The toxic manifestations that have been described with the nonsteroid oral estrogens did not occur.