This invention discloses compounds useful as steroid sulfatase inhibitors. The compounds comprise the formula (1) ##STR1## wherein (a) R is selected from the group consisting of hydrogen, a lower alkyl group, an alkoxy group, halogen, NH.sub.2, NO.sub.2, C.tbd.N and N.dbd.C.dbd.S; and (b) the ring system ABCD is a steroid nucleus selected from the group consisting of estrone, dehydroepiandrosterone, estradiols, estradiolesters, pregnenolone, substituted estrones, substituted dehydroepiandrosterones, substituted estradiols, substituted estradiolesters and substituted pregnenolone. The compounds also comprise the formula (5) ##STR2## wherein (a) R.sub.1 is hydrogen and R.sub.2 is selected from the group consisting of SO.sub.2 CF.sub.3, SO.sub.2 NH.sub.2, SO.sub.2 (C.sub.1 -C.sub.6 -alkyl), COCF.sub.3, CONH.sub.2, CO(C.sub.1 -C.sub.6 -alkyl); and (b) the ring system ABCD is a steroid nucleus selected from the group consisting of estrone, dehydroepiandrosterone, estradiol, estradiolester, pregnenolone, substituted estrones, substituted dehydroepiandrosterone, substituted estradiols, substituted estradiolesters and substituted pregnenolone. The invention also discloses methods of treating a patient therapeutically and prophylactically for estrogen dependent diseases with the compounds of this invention.