Current-voltage characteristics were studied for polypyrrole films contacted with different electrolytes in aqueous form and complex polymer solid electrolytes. Cyclic voltammograms for the conducting polymer in aqueous medium exhibited the typical oxidation and reduction peaks, whereas for solid polymer electrolytes, there was large asymmetry in curves; with the anodic current being much higher than that in the cathodic region. A rapid switching-type response was noted in the case of polyethylene oxide-cupric chloride complex as solid electrolyte. This effect was pronounced when the same complex contained the polypyrrole deposited within it as a composite. These various results have been discussed in the light of different energy levels in the conducting polymer and the contacting medium, as well as the formation of a microdispersed system with higher charge transport. © 1999 John Wiley & Sons, Inc.