The cost of composite materials limits the use of these materials. For this reason, many studies have been done with composites to reduce costs. In this study, the filler effect on vinylester matrix composites was investigated in order to contribute to cost reduction. Calcium carbonate (CaCO3) and aluminum hydroxide Al(OH)(3) were used as filler, and E-glass was used as reinforcement material. In addition, the filler ratio, which was added to the structure, was 5 wt.-%, 10 wt.-% and 15 wt.-%. The production method was vacuum infusion, and the manufacturing of the composite plates completed. A tensile test, bending test, hardness test and ash test were performed on the samples. Also, microstructural images were examined by scanning electron microscope. Finally, it was found that 15 wt.-% CaCO3 filler increased hardness considerablely. Tensile properties and flexural strength properties did not change dramatically with the addition of filler. Moreover, the addition of filler decreases the cost of the composite. Thus, when we compare the cost effectiveness of fillers, CaCO3 filler on a vinylester matrix composite is advantageous for decreasing cost.