In the following essay the results of the research on nucleation of polypropylene obtained in PKN Orlen SA were presented. Both, organic (Millad 3988, ADK NA21) and non-organic (talc) mediums were used in the process. The main aim of the examination was to measure the influence of the above-mentioned mediums on the structure and physicochemical features of polypropylene. It has been proved that the organic nucleation mediums are more efficient as not only did polypropylene become more transparent, its structure more homogenous but his melting temperature increased as well. All those changes demonstrate that the nucleation process has taken place. The favourable changes in the polymer macrostructure were enabled by the process of nucleate molecules in the process heteronucleation.