This paper outlines an investigation of the electrochemical behaviour of polymeric divinylferrocene (PDVF) produced by direct polymerisation of divinylferrocene (DVF) monomer on a glassy carbon substrate. The findings indicate that PDVF undergoes reversible reduction/oxidation in neutral and acidic aqueous media containing Perchlorate (ClO4-) and sulfhate(SO42-). The anodic peak potential of the PDVF shifts linearly to less positive potentials as the sulfuric acid (H2SO4) concentration is increased from I to 5 M. The polymer film strongly adheres to the glassy carbon surface and is electrochemically stable when subjected to repeated voltammetric cycling in the potential range of -0.2 to +0.8V vs. Ag vertical bar AgCl. The potential of the partially oxidized film of PVDF on a glassy carbon substrate against a Ag vertical bar AgCl/KCl reference electrode in sulfuric acid solution is stable, reproducible and varies linearly with the acid concentration in the range of 1-5 M. This observation may be suitable for potentiometrically measuring the state-of-charge of lead-acid batteries. Crown Copyright (C) 2008 Published by Elsevier B.V. All rights reserved.