The impedance response of polymers derived from aryl amines and ring-substituted aryl amines shows a CPE behavior at low frequencies with alpha between 0.5 and unity. In this work, the dependence of the CPE behavior of a poly-o-toluidine film on its thickness, on the applied potential and on the electrolyte concentration is reported. The alpha dependence on the thickness is explained through the correlation between the film thickness and the film morphology. The alpha dependence on the applied potential is explained by a change in the mechanism of charge transport in the polymer, with the potential.