The electrochemical impedance spectra of poly(para-phenylene) (PPP) films prepared potentiostatically in 0.1 M tetra(n-butyl ammonium) tetrafluoroborate (TBABF4) acentonitrile solution have been examined. Charge transfer resistance was very low at the oxidized state, which is in agreement with the conductive behavior when the polymer is oxidized. The corresponding exchange current density was very high. Values of the capacitance associated with the polymer varied as a function of the film thickness and the electrode potential. The experimental impedance data have been fitted to an equivalent electrical circuit. It was therefore possible to follow the changes of the parameters of the mass transport, charge transfer and double layer with the redox states of the polymer. The effect of experimental conditions on the impedance response of the polymer film was also studied.