3,4-diphenylsalicylaldoxime and 3,4-diphenylanthranylaldoxime derivatives, containing small groups (methyl or ethyl) on the imine carbon atom, were synthesized and submitted to biological assays. Binding tests performed on uterine cytosol estrogen receptor (ER) preparation and on purified full-length human ERalpha and ERbeta, showed that the newly synthesised compounds exhibit considerably lower binding affinities with respect to reference non-substituted 3,4-salicylaldoxime.