A thermosetting composition comprising (a) 97 to 40 percent by weight of at least one bis(dihydrobenzoxazine) prepared by the reaction of an unsubstituted or substituted bisphenol with at least one unsubstituted position ortho to each hydroxyl group, formaldehyde and a primary amine; and (b) 3 to 60 percent by weight of at least one bisphenol, wherein the percent by weight refer to the total amount of components (a) and (b), with the proviso that (a) and (b) add up to 100 percent by weight; and (c) optionally other components. Cured products made from these compositions have valuable chemical, physical and mechanical properties.