A bisphosphonic acid of the general formula (I) ##STR00001## wherein R.sup.1 is H, OH, C.sub.1-C.sub.6 alkyl C.sub.1-C.sub.6 alkoxy, C.sub.1-C.sub.6 hydroxyalkyl, C.sub.1-C.sub.6 aminoalkyl, C.sub.1-C.sub.6 halogen alkyl X is a direct bond, alkylen group with 1 to 20 carbon atoms, (CH.sub.3).sub.m--(OCR.sup.3HCH.sub.2).sub.n--(O).sub.o--, wherein R.sup.3 is H or CH.sub.3 and m is 0 or a number from 1 to 6, n is a number from 1 to 10, preferably 1 to 6, and o is 0 or 1, --(CR.sup.4HCH.sub.2O).sub.p--, wherein R.sup.4 is H or CH.sub.3, p is a number from 1 to 10, preferably 1 to 6, (CH.sub.3).sub.q--(OCR.sup.5HCH.sub.2).sub.r--(O).sub.s--(CH.sub.3).sub.t- --, wherein R.sup.5 is H or CH.sub.3 and q is 0 or a number from 1 to 6, r is a number from 1 to 10, preferably 1 to 6, and s is 0 or 1, and t is a number from 1 to 6, R.sup.2 is a group of the formula (II) ##STR00002## as well as their physiologically compatible derivatives in particular salts and trimethyl silyl derivatives.