The preparation and characterization of poly(aryl ether sulfone) (PES) PolyHIPE (polymerized high internal phase emulsion) materials is described. A maleimide-terminated aryl ether sulfone macromonomer was copolymerized with styrene, divinylbenzene (DVB), or a bis(vinyl ether) species, in the continuous phase of a HIPE. Furthermore, a novel, nonaqueous HIPE methodology was employed, since only dipolar aprotic solvents were able to cosolubilize the polymeric precursor and surfactant. HIPEs of petroleum ether, dispersed in a dipolar aprotic solution of maleimide-terminated PES, PEO-PPO-PEO block copolymer surfactants, comonomer, and AIBN, were successfully prepared and polymerized. The cellular structures and porosities of the resulting materials were characterized by SEM, solvent imbibition, mercury porosimetry, and a Brunauer-Emmett-Teller (BET) treatment of nitrogen adsorption results. All were shown to possess an open-cellular morphology and a secondary pore structure within the polymer walls. Thermogravimetric analysis (TGA) of the materials indicated that critical degradation occurred at higher temperatures than in poly(styrene/DVB) PolyHIPE but lower than the PES macromonomer precursor.