Gold(111) electrodes modified with Self Assembled Monolayers (SAMs) of 4-Aminothiophenol (4-ATP) functionalized with Pd(II) colloid nanoparticles, have been constructed, characterized and used as template for the electropolymerization of aniline (PANI) films. Cyclic voltammetry and UV-vis spectroscopy confirm the functionalization of the 4-ATP SAMs by Pd(II) complex nanoparticles. Atomic Force Microscopy (AFM) images and the cyclic voltammetry measurements reveal that polyaniline films grown on 4-ATP-Au(111) SAMs functionalized with Pd(II) complex nanoparticles, posses a nanostructured morphology constituted by globular structures of nanometric size. The electropolymerization of PANI driven by repeated potentiodynamic cycles produces structures with average diameters in a range of 20 to 60 nm.