The electropolymerization process of pyrrole in aqueous acid medium at a gold polycrystalline electrode was followed in situ by uv-visible differential reflectance spectroscopy (UVDRS). This allows us to observe the early stages of polymerization and to monitor the film growth as a function of the number of potential cycles, or of the time of polarization at a fixed potential. The redox properties of the films were also investigated, and the uv-visible absorption bands were assigned according to the results of the literature. The effect of the incorporation of iron tetrasulfonated phthalocyanine into the polypyrrole films was also observed by UVDRS as a function of time, potential and number of cycles.