The investigation of ceramic filler on the properties of denture base materials made from PMMA filled with Al2O3/ZrO2 was carried out. The amount of Al2O3/ZrO2 filler was fixed at 5 wt%. However, the ratios of Al2O3 to ZrO2 added were varied from 0 to 100. Samples were prepared for fracture toughness and flexural test. The findings were analyzed using scanning electron microscopy (SEM). The findings were recorded that the Al2O3/ZrO2 ratios show higher fracture toughness and flexural properties than PMMA matrix. SEM micrographs indicate that distribution of Al2O3 and ZrO2 in the PMMA matrix is fairly homogeneous. The mixing method was good between reinforcement particles and PMMA matrix. Therefore, addition of six ratios of Al2O3/ZrO2 with PMMA and this mixture is able to improve the mechanical properties of this denture base material.