PolyHIPEs are cellular materials obtained by polymerization within High Internal Phase Emulsions (HIPEs). The continuous phase of the emulsion is constituted of monomers and the volume of the dispersed phase (water) is superior than 74 % in respect to the total volume of the emulsion. The polymerization occurs in the continuous phase to create the polymer matrix and the dispersed phase induces the porosity. The polymers obtained are macroporous with pore sizes greater than 10 µm. Due to their low density and their high interface, polyHIPEs are used in several applications, such as drug encapsulation, supports for catalysts, and supports for the immobilization of bio-molecules, etc. PolyHIPEs are generally obtained by free-radical polymerization; that restricts the choice of monomers mainly to styrene and its derivatives and to acrylates. The majority of high performance polymers are not obtained by free-radical polymerization. Therefore, it is of great interest to extend the variety of monomers used to synthetize polyHIPEs using polycondensation.The objectives of this work are to synthetize and characterize polyHIPEs obtained by step growth polymerization: polycondensation or polyaddition in concentrated emulsion. Achieving a step polymerization without destabilizing the HIPE is a great challenge. Step polymerization requires extreme reaction conditions such as high temperatures and long reaction durations. Additionally, upon polycondensation a by-product is produced that has to be removed from the reaction media to achieve good yields. In order to successfully perform a polycondensation/polyaddition within the emulsion, we first focused on the synthesis of porous polyurethanes. Monomers were selected according to their Hydrophilic Lypophilic Balance (HLB) and synthesized. A stable emulsion was formulated and subsequently the polymerization was initiated by adding a catalyst. Macroporous polyurethanes were obtained and the homogeneity of the morphology was optimized.