The electro-oxidation reactions of polysilane copolymers with pendent ferrocenyl groups, Fc, of the type, [FcSiCH3)(PhSiCH3)n]m where n = 5, 7, and 25 were studied using thin films of the polymer on a platinum electrode immersed in acetonitrile electrolyte. The cyclic voltammograms reveal two oxidation reactions. The first represents the reversible oxidation of the ferrocenyl group and has a peak appearing at 0.40V anodic of NaSCE, while the second oxidation, has a peak anodic current at 1.15V for n = 7 (12.5 mole percent [m/o] FcSiCH3), and corresponds to the oxidation of the polysilane backbone. The redox properties of the pendent ferrocene group show minimal interaction with the polysilane chains. The ferrocenyl group does, however, affect both the stoichiometry and anodic wave forms for the oxidation reaction of the polysilane backbone. For example, the oxidation peak is shifted anodic by 150 mV, consistent with the expected coulombic effect of the ferrocenium ions on the polymer. From a comparison of the charge associated with the two reactions, the electrochemical stoichiometry of the irreversible oxidation reaction of the polysilane is calculated to be one electron per 21 monomer units. © 1990, The Electrochemical Society, Inc. All rights reserved.