New supported polypyrrole nanocomposites have been prepared and studied in this work. Self-supported sheets of fibrous cerium(IV) hydrogenphosphate (CePf) were used as the inorganic matrix, since the fibrous morphology presented by this material makes molding possible, giving a desired shape to the final polypyrrole/ CePf conducting nanocomposites. The influence of pyrrole concentration on the nanocomposite preparation was studied, as well as the influence of CePf on the polypyrrole characteristics. XRD, Raman, SEM and conductivity measurement data show the conducting polypyrrole coating CePf fibers, yielding self-supported sheets of organic-inorganic conducting nanocomposites.13613781383