Doped polypyrrole is a conducting polymer. Polypyrrole films are usually prepared by electrochemical methods. Here we report the deposition of polypyrrole thin films on glass substrates using the RF plasma polymerization method and its optical characterization. We also show that the optical band gap of polypyrrole films decreases from 2.8 eV to 0.8 eV as a result of iodine doping.