Experiments have shown the feasibility of new composite electrodes ECP(Ox) resulting from the dispersion of nanoparticles of a metal oxide (Ox) into an electrically conductive polymer (ECP). In this preliminary work, Ox was a spinel mixed valence oxide of copper and manganese, Cu1.4Mn1.6O4, and ECP was polypyrrole. The intimate mixing of the two materials modified neither the ECP charge-transfer and transport behavior nor the electrocatalytical activity of the oxide. These composite electrodes exhibited a remarkable stability, even in acidic media, in contrast to noncomposite electrodes of the same oxide.