Iodine doping of polyethylene terephthalate (PET) has been made to develop intrinsically conducting plastic films. The doped material is investigated in terms of structure and morphology, electrical and optical characteristics. Considerable decrease in the value of the degree of crystallinity is observed on doping the samples. Further there are discernible shifts found in the energy gap and band edge towards lower energies on doping with iodine. The refractive index of the complex films is also found to increase.