Abstract Composite thin films of polyaniline hydrochloride (PANI-HCl) with poly(methyl methacrylate) (PMMA) and polystyrene (PS) have been synthesized via a modified interfacial polymerization technique. The morphology of such laminate films can be described adequately as a thin film of PMMA of PS coated on one side with an ultra-thin continuous layer of electroactive PANI-HCl with conductivity in the region of 10 S cm −1. XPS studies reveal the depth of the layer to be at least 60 Å. Chloride ions associated with both amine and imine nitrogens were identified. Covalently-bonded chlorine and molecular HCl were also identified on the film surface. The doping level in the PANI-HCl layer is about 20% in PMMA-PANI-HCl and 18% in PS-PANI-HCl respectively. These laminate films couple the excellent mechanical properties of the substrate with the interesting properties of polyaniline.