This work is focused on plasma treatment of polypropylene (PP) and deposition of Au layer by sputtering and evaporation. Samples were exposed to argon plasma discharge (8.3 and 3.2 W) and the changes of the surface properties were studied by different analytical methods. Surface wettability was derived from contact angle. PP was metallized with sputtered and evaporated Au layer. Surface morphology was measured with atomic force microscopy. The Au layers were deposited by sputtering and evaporation. The thickness of the deposited Au layers was determined by atomic absorption spectroscopy. The mechanical properties of deposited Au layers were analyzed using NanoIndenter device, the surface morphology of scratches in Au was studied by SEM microscopy. The significant difference in the zeta-potential at all pH range between pristine and plasma-treated PP clearly indicates the effect of plasma treatment leading to a more hydrophilic surface. The surface modification of the PP substrate, even the wettability of surface and its roughness are modified, is not capable of significant changes in substrate-metal nanoparticle interaction, since the thickness of gold nanolayers is slightly influenced by substrate premodification. Both sputtered and evaporated gold nanolayers on pristine PP become electrically conductive for thickness from ∼8 nm. POLYM. ENG. SCI., 53:2270–2275, 2013. © 2012 Society of Plastics Engineers