In this study acrylonitrile-butadiene-styrene (ABS) terpolymer was reinforced with glass fiber. The effects of glass content on the tensile properties of the composites were examined. Increasing the glass content in the ABS matrix from 10 wt% to 30 wt% resulted in improved tensile strength and tensile modulus. To obtain a strong interaction at the interface, SiO2 at varying concentrations was introduced into the GF composite. The incorporation and increasing amount of SiO2 in the composites increased tensile properties of the ABS/ SiO2/GF systems due to the improved adhesion at the interface,. These results were also supported by scanning electron micrographs of the ABS/ SiO2/GF composites, which exhibited an improved adhesion between the GFs and the ABS matrix.