Copper injected anodically into eutectic Na-K nitrate melt at 300-degrees-C is shown to deposit cathodically as cupric oxide (CuO). The dissolved copper is in the +2 oxidation state and apparently forms a nitrato complex that facilitates reduction of nitrate to oxide (and nitrite) at potentials more than a volt positive of that for reduction of the Na/K nitrate species. From these results and literature studies, cathodic metal oxide deposition from nitrate melts appears to be a general phenomenon that could prove to be a practical means of preparing anhydrous metal oxide films.