Among various nanofillers for composite systems, carbon-based fillers such as graphite, carbon fibers, carbon black, carbon nanotubes, graphene, etc. are attracting great attention in both academia and industry for the advent of highly integrated electronic devices. The objective in fabricating such composite materials is to obtain distinct properties evolved from the synergistic effects of the component materials that may be exploited for various applications such as electronics and optical devices. In the present work, polyurethane/graphite composites have been synthesized with the aim of using them for electromagnetic shielding applications. The polyurethane/graphite composites were prepared through an in situ polymerization method in the presence of graphite nanoparticles. The prepared composites were characterized by scanning electron microscope, transmission electron microscope (TEM), and x-ray diffraction techniques. The shifting of the major peak of graphite nanoplatelets (GNPs) in prepared nanocomposites towards the left from 26.336A degrees d-spacing = 3.381 to 25.374A degrees d-spacing = 3.507 on a 2 theta scale indicates the intercalation type of dispersion in the prepared nanocomposites. This was further validated with the TEM characterization. The introduction of GNPs in polyurethane (PU) during in situ polymerization creates an electrical network in the resulting composite, which therefore makes it highly conductive. The prepared nanocomposite showed an electrical network at 2.2 vol.% of the percolation threshold in DC condition and a similar percolation threshold was found at 100 Hz in AC conditions. The maximum conductivity found at 6.5 vol.% of filler loading was 0.01 S/cm. The resulting composites were evaluated for electromagnetic interference (EMI) shielding at different filler loadings. The prepared PU/GNPs composites were found to be highly effective with shielding effectiveness of 19.34 dB, and with electromagnetic interference shielding materials at 0.9-1 GHz.