The authors report on the changes of the electrical, morphological, chemical and electrochemical properties of polypyrrole dodecylsulfate films aged at 100-degrees-C or exposed to a solar simulator light source. The thermal aging induces a loss of conductivity and a gradual decrease of the anodic and cathodic peak currents, as measured by cyclic voltammetry. Irradiation does not substantially alter the properties of the films; the conductivity does not change and the electroactivity is slightly modified. Degradation of the properties is attributed to cross-linking, oxidation and evaporation of low molecular weight oligomers.423317321