Abstract The electropolymerisation of the iron(III) salen complex is reported, as well as the electrochemical behaviour of the monomer. High scan rate cyclic voltammetry allows us to calculate the lifetime of the cation radical generated during oxidation. Although the films are more difficult to prepare than several other poly(metal–salen) films (e.g. with nickel or copper), poly(iron–salen) can be well characterised by electrochemistry, either in organic or aqueous medium. The efficiency of the films towards the catalytic electroreduction of hydrogen peroxide and oxygen has been tested, and a different kinetic behaviour has been observed for both substrates, with a much greater efficiency in the case of oxygen.