The electrocatalytic reduction of Fe(III) was investigated using a carbon fibre microelectrode modified with a ruthenium oxide hexacyanoferrate film (RuOHCF/CFM). At surfaces containing this chemical modifier, Fe(III) is electrocatalytically reduced at 0.0V without interference from Fe(II), hence allowing the speciation of Fe(III). A linear relationship between the cathodic current and concentration of Fe(III) was obtained by amperometry in the range 10–210μmolL −1 with detection and quantification limits of 0.22 (S/N=3) and 0.74 (S/N=10)μmolL −1 , respectively. The described amperometric method was successfully applied for the determination of Fe(III) in different wine samples.