The study of the relative binding affinity (RBA) to the human alpha and beta estrogen receptors (ERs) of various 7-hydroxycoumarins substituted at 4- and 3,4- positions is weak and lacks in selectivity for both ERalpha and ERbeta. The 4-(4-hydroxyphenyl)-7-hydroxycoumarin shows a weak RBA to ERbeta and 3,4-diphenyl-7-hydroxycoumarin presents a stronger RBA to ERalpha than ERbeta.