The purpose of the present work was to analyze the development of Si3N4-SiC(w) ceramics composites containing via gas-pressure sintering aiming the alternative processing route, of the low cost, for this materials. For comparison, the hot uniaxial pressed sintering was utilized. Both sintering process were performed under nitrogen atmosphere, at 1750 degreesC with 20 degreesC/min and characterized with respect to specific gravity, crystalline phases, microstructural analysis, microhardness and fracture toughness. The gas-pressure Si3N4-SiC(w) sintered presented better results of the density and mechanical properties for 10 vol.% SiC(w) composition. On the other hand, observed the decrease significantly of the densification rate due whiskers interference on matrix grains rearrangements and volumetric retraction for 20 vol.% SiC(w) compositions. Therefore, believed that modifying the processing parameters utilized in this process, such sintering time and temperature, the improve the density and mechanical properties for compositions to higher SiC(w) content are expected.