Selective laser sintering (SLS) is a powder based additive manufacturing technology, and one of the most promising technologies currently in use for the manufacturing of medium sized series of functional parts. However, the availability of suitable materials is still very limited, with polyamide-based materials taking up the lion’s share of consumption. Recently, a number of polypropylene materials has come onto the market as an addition to the SLS materials portfolio. The current study focused on the improvement of mechanical properties of one of these materials by fiber reinforcement, a method well known in traditional polymer processing. In a systematic manner, varying amounts of wollastonite and glass fibers of different lengths (~50 – 150 μm) were dry blended with two varieties of bonding agents and the polypropylene powder. The processability on an SLS machine of the produced blends was assessed, and the mechanical properties of produced parts were determined via tensile and impact resistance tests. Additionally, the nature of fracture was investigated using microscopy. Through simple dry blending, homogeneous distributions of fibers could be achieved. It was found that both fiber length and amount play a critical role with respect to powder flowability, and therewith processability. In addition, the nucleating effect of wollastonite fibers caused a narrowing of the processing, or sintering window. Since the fibers were all assumed to be shorter than the critical length, the most important parameter to be influenced is adhesion of the fibers to the polypropylene matrix. The adhesion was found to depend largely on choice of the bonding agent and its particle size distribution, and could be improved by changing certain process parameters. Ultimately, it was possible to produce parts that showed both increased tensile modulus and strength, in comparison to unfilled materials.