Impact test determines the amount of energy absorbed by a material during fracture. This energy may be used to determine the impact strength or impact resistance of the material depending on the test that was performed and the characteristic that is to be determined. These values are important for the selection of materials that will be used in applications. Impact test of matrix material allows comparing quantitatively the relative values of the damage resistance parameters for composite materials with different volumetric filling ratios. The main purpose of this study was an investigation and comparison of the influence of PET (Polyethylene Terephthalate) fibres and Soft wood fibres (WEHO 500), as well as their hybrid combination on the impact strength of the reinforced composites based on polypropylene matrix. For this purpose injection moulding grade polypropylene HP400R was applied as a matrix polymer. The manufactured composite compounds were subsequently injection moulded into test specimens.