Conducting copolymers of imidazole and carbazole were chemically synthesized in various molar ratios of the imidazole and carbazole by chemical oxidative polymerization in acetonitrile medium using ammonium per-sulphate as oxidant. The selection and composition of solvent, concentration of the monomer, polymerization time, and temperature were optimized to obtain better quality and yield of the copolymers. The synthesized conducting copolymers were characterized by various techniques such as UV-visible, Fourier transform infrared, H-1-NMR, and X-ray diffraction spectroscopy. The solubility of the copolymers was tested in various solvents. Their conductivity was tested at various temperatures. The thermodynamic stability of the copolymers was examined by differential scanning colorimetric and thermogravimetric analysis. The copolymers show comparatively higher conductivity, better solubility, and higher thermal stability than the homopolymer poly(carbazole) and lower than that of poly(imidazole). (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 119: 2824-2833, 2011