The possibility of electrochemical synthesis of nanocomposites and nanocomposite films at pure-iron and steel electrodes using a 1-vinylimidazole–acrylic-acid co-polymer in the presence of chitosan is shown. Using UV- and IR-spectroscopy, XRD- and elemental analyses, the nanocomposite’s structure and composition were elucidated. The nanocomposite solubility was shown to be determined by intramolecular interaction of macromolecules in the 1-vinylimidazole–acrylic-acid co-polymer with gold nanoparticles. The nanocomposite thermal decomposition is a multistage process.