In the present work, the ionic transport in copper tetrasulfonated phthalocyanine doped polyaniline (PANI/CuTsPc) film and its effects on the optical properties of the polymer is presented. The studies were performed in situ and in real time by using electrochemical surface plasmon resonance (ESPR) and electrochemical quartz crystal microbalance (EQCM). The electropolymerization was performed by potentiodynamic method and the EQCM experiments showed that the PANI/CuTsPc films behave rigidly validating the use of the Sauerbray equation. Both protonic and anionic participation in the charge compensation process were calculated and showed that the presence of the CuTsPc in the PANI film suppress the anionic transportation. Finally, the ESPR experiments showed that changes in the optical properties of the PANI/CuTsPc film were more expressive in the same potential range where the protonic transport was dominant. (c) 2006 Elsevier B.V. All rights reserved.