Complex anodic alumina films are formed by pore-filling (reanodization) of porous anodic films (matrices). These films are characterized by electrochemical impedance spectroscopy. It is determined that the recorded impedance spectra are well described by an equivalent circuit, containing a Constant Phase Element. The fitted parameters of the complex films are calculated, and information about certain dielectric characteristics of these films in contact with an electrolyte is obtained. The paper also discusses changes in the surface non-homogeneity of the complex films in comparison with those of the porous matrix. (c) 2006 Elsevier B.V. All rights reserved.