Abstract. Colloidal dispersions and thin films containing poly-N-(epoxypropyl)carbazole (PEPK) and Ag-Au nanoparticles (2-3 nm in diameter) were prepared and investigated by TEM, optical and IR spectroscopy, and electrophysical tools. The introduction of nanoparticles results in cooperative phenomena between the polymer and the Ag-Au particles; as a consequence these particles increase the electrical conductivity of the nanocomposite films by at least one order of magnitude, even in very low concentrations.