We report an alternative method to modify talc for use in the fabrication of composites of polypropylene (PP) and talc. Grinding pulverization is employed to prepare talc fillers (referred to hereafter as p-talc). The properties of composites made with p-talc compare favorably with composites made with pulverized talc that has been further treated with a silane coupling agent (referred to as s-talc). The morphology of PP/p-talc composites illustrates particle orientation and a uniform dispersion of pulverized talc in the PP matrix. Modulated DSC analysis shows the ability of p-talc and s-talc to nucleate PP crystallization. The mechanical properties (i.e., the dynamic modulus, tensile strength, and impact resistance) of the PP/p-talc composites are very similar to PP/s-talc composites. The modification of talc by grinding is thus a highly effective alternative method to prepare PP/talc composites that does not require chemical treatment of the talc. The pulverization method is simpler and less expensive in comparison to silane treatment. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007