Reinforcing thermoplastics with short fibers is a common way to improve the mechanical properties in different ways and was investigated for many years. Adding short glass fibers with a high strength and high modulus to a thermoplastic material leads to a raise of the strength in the compound but also decreases the strain at break. Cellulose fiber composites show a higher strain at break and a higher Charpy impact strength due to long fiber pull outs. Mixing these two fibers with their different characteristics in one compound opens a large field of opportunities. To make use of both fiber properties, the interface between the fiber and the matrix is important and has to be tailored for each fiber. The study will show the effect on mechanical properties of a compound reinforced with two different types of fibers. Polypropylene PP 575P was used as matrix material and glass fibers (GF) and cellulose fibers (Cell) were used as reinforcement. Three different ratios (2:1 GF/Cell, 1:2 GF/Cell and 1:1 GF/Cell) of each type of fiber mixed by dry blending were investigated with the same fiber volume content in the composite. Injection molded specimen were manufactured to evaluate tensile and Charpy impact properties. SEM pictures show the fiber matrix adhesion especially with regard to the fracture mechanism of each fiber. It was shown that the hybrids with cellulose fibers show an increase in elongation at break and Charpy impact properties compared to glass fiber composites. Furthermore, 33% of glass fibers in a cellulose reinforced polypropylene leads to a higher tensile strength and Young’s Modulus. The break surface of the hybrid composites show fiber pull outs for cellulose fibers as well as fiber breaks for glass fibers. That indicates the intended tailored fiber matrix adhesion.