The world of organic coatings has been quickly revolutionised by the use of graphene due to this material’s unique properties (e.g. impermeability, high surface area, high aspect ratio and low cost) which make it an ideal candidate for anti-corrosive barrier coatings [1-6]. Polymer/graphene nanocomposite formulations have been prepared with commercially available graphene nanoparticles, i.e., XGnP® 5M, 15M and 25M (XG Sciences, Inc., Lansing, Michigan, USA) with flake diameters of 5 µm, 15 µm and 25 µm, and a thermosetting polymer matrix, i.e., BPA free coating, Gold Lacquer (AkzoNobel, Packaging Coatings Ltd., UK). The polymer/graphene formulations were coated onto electrolytic chromium coated steel (Crown Packaging UK Plc) using a spin coater. Electrochemical tests were performed in a 0.1 M NaCl solution, using a conventional three electrode system. Electrochemical impedance spectroscopy tests showed that the presence of graphene improved the corrosion resistance of the materials with flake diameter strongly affecting the performance of the coating.