Electrochemical polymerization of N-vinylcarbazole (NVC) on platinum electrodes was studied. Effects of concentration, electrode area, polymerization potential, and solvent on the polymerization rate were discussed. Insulating and conducting polymers of NVC can be simultaneously prepared depending on the electrolysis conditions. The insulating PNVC cannot only be converted into a conducting one but can also be blended with other conducting polymers such as polythiophene and polypyrrole. Soluble insulating polymers of NVC were characterized by FTIR, NMR, and DSC studies. Conducting polymers were characterized by FTIR and 4-probe conductivity measurements.