The electrodeposition of polypyrole from an aqueous solution containing a fluoride salt as supporting electrolyte is associated with a self passivation of the electrode, caused by an unusually low conductivity of the polymer. Conductivity values are deduced from impedance data and from a special analysis of the cyclovoltammograms recorded during the potentiodynamic synthesis. Ion exchange experiments, the deposition from mixed KF/KCl electrolytes as well as the completely different behaviour during poly(N-methylpyrrole) deposition lead to the conclusion that the positive charges in oxidized polypyrrole fluoride films are not located on the polymer backbone, but on the hydrogen atom of the pyrrole nitrogen. This system is stabilized by hydrogen bonds to the fluoride ion.