Porous polymeric materials having a very high content of thermally conductive and/or electrically conductive fillers. Process for the preparation of the porous composite material including at least one binder-forming polymeric phase and one or more fillers, this process including the stages of hot mixing, by the molten route, the polymeric phase, the fillers and a sacrificial polymeric phase, so as to obtain a mixture, of shaping the mixture and of removing the sacrificial polymeric phase.