Polymer composites reinforced by both the micro and nano fillers is the subject of this paper. Polypropylene (PP)–nylon micro-fibre composites modified with nanosilica and modified nanosilica (using silane coupling agent) were prepared by melt compounding. The nanosilica prepared in the laboratory was used as reinforcing filler in PP–nylon fibre composites. The compounding characteristics and mechanical properties of the composites were studied. The equilibrium torque during compounding increased with the addition of nanosilica and modified nanosilica. The use of two types of fillers leads to synergistic effect on the mechanical properties of the composite. Composites with 1wt.% nanosilica and 30wt.% nylon fibre show high tensile strength, tensile modulus, flexural strength and flexural modulus. Composites modified with 1wt.% nanosilica and 10wt.% nylon fibre–PP composite show higher impact strength.