The electrodeposition of PbO2 on Pt in the presence of F- and Fe(III), separately or together in the growth solution, is examined. The electrodeposition follows the same reaction scheme previously reported in the literature for PbO2. The electrocatalytic activity of the resulting oxides is assessed for the reactions of O-2 and O-3 evolution. Fluoride and iron into PbO2 have different effects on the electrocatalytic activity of PbO2 for O-2 evolution and O-3 formation. With F-PbO2 the first process is favoured and the second one inhibited, whereas with Fe-PbO2 electrodes we observed the opposite trend. Lead dioxide grown from F- and Fe(III) containing solutions showed the highest activity for O-3 formation. The larger amount of iron incorporated into PbO2 in the presence of F- is proposed as a possible cause of the enhanced activity for ozone formation of (F-Fe)-PbO2 electrodes.