High temperature, polymeric, structural foams were prepared using a high internal phase emulsion (HIPE) to copolymerize styrene with maleimide based monomers. In this work, N-ethylmaleimide and a bismaleimide (BMI) monomer, bis(3-ethyl-5-methyl-4-maleimide-phenyl) were successfully free-radically copolymerized with styrene in a water-in-oil HIPE to produce polymeric foams with glass transition temperatures (T(g)s) ranging from 140 to 220 degrees C depending on composition. The ethylmaleimide and BMI were uniformly Incorporated throughout the polymer, which allowed the thermal performance of the foams to be tailored by controlling the concentration of ethylmaleimide and BMI modifiers. In addition, the thermal oxidative stability of the foam systems increased with increasing concentration of maleimide based monomers. The resulting polymeric foams contained an open cell morphology with cell sizes of approximately 10 mu m in diameter. Compression tests of the high temperature foam systems showed that compression strengths of approximately 700-850 kPa were obtainable at foam densities under 80 mg cm(-3) (5.0 lb ft(-3)).