Hysterectomized women were administered tritiated-17alpha-ethinyl estradiol either iv or orally and their urine collected and assayed for labeled-metabolites. Over 95% of the recovered activity was found as conjugated steroids. These were separated into 4 groups by Sephadex LH-20 chromatography with chloroform-methanol and .01M NaCl. 2 of the groups were almost entirely glucosiduronates. 17alpha-ethinyl estradiol itself was the major component in 3 of the fractions while 2-methoxy-17alpha-ethinyl estradiol was the major component of the 4th. Hydrolysis, chromatography with benzene-methanol, and further purification of each of the 4 fractions yielded similar metabolite patterns. Of the major compounds identified, 5 were ethinyl compounds: 17alpha-ethinyl estradiol, 2-methoxy-17alpha-ethinyl estradiol, 16 beta-hydroxy-17alpha-ethinyl estradiol, 2-hydroxy-17alpha-ethinyl estradiol, and 6 alpha-hydroxy-17alpha-eithinylestradiol; 4 were deethinylated estrogens: estrone, estreadiol-17beta, estriol, and 2-methoxy-estradiol-17 beta.