This study looked into the morphology of novel mesoporous divinylbenzene polymers with extremely high surface areas, both in the dry state using a conventional nitrogen adsorption/desorption method and in the swollen state by inverse steric exclusion chromatography. By comparing the dry- and swollen-state morphologies it was possible to obtain a more comprehensive understanding of the porous structure of the material. The novel poly(divinylbenzene) was found to have a foam-like morphology in which the polymeric matrix formed a continuous phase with thin walls surrounding bubble-like cavities generated by a microsyneresis mechanism. Such a morphology is completely different from that of other styrenic polymers with high-surface areas.