The influence of the preparation method on the performance of RuO₂–Ta₂O₅ electrodes was evaluated toward the ethanol oxidation reaction (EOR). Freshly prepared RuO₂–Ta₂O₅ thin films containing between 30 and 80at.% Ru were prepared by two different methods: the modified Pechini–Adams method (DPP) and standard thermal decomposition (STD). Electrochemical investigation of the electrode containing RuO₂–Ta₂O₅ thin films was conducted as a function of electrode composition in a 0.5-moldm⁻³ H₂SO₄ solution, in the presence and absence of ethanol and its derivants (acetaldehyde and acetic acid). At a low ethanol concentration (5mmoldm⁻³), ethanol oxidation leads to high yields of acetic acid and CO₂. On the other hand, an increase in ethanol concentration (15–1000mmoldm⁻³) favors acetaldehyde formation, so acetic acid and CO₂ production is hindered, in this case. Electrodes prepared by DPP provide higher current efficiency than STD electrodes for all the investigated ethanol concentrations. This may be explained by the increase in electrode area obtained with the DPP preparation method compared with STD.