Electrodeposition of ZnZr and ZnV oxide composites was performed under galvanostatic conditions at 313 K on unagitated pH 2 sulfate solutions containing Zn 2+ and Zr 4+ or VO 2+ ions and an additive such as polyethylene glycol (PEG). The effects of PEG addition on the codeposition of Zr and V oxides and their polarization behavior, and on the microstructure of the deposits, were investigated. Although the Zr content in the deposits obtained from the ZnZr solution in the absence of PEG was approximately zero, it increased significantly at a current density of above 1000 A•m ¹2 following the addition of PEG. In the ZnV solution, the V content in the deposits obtained from 100 to 2000 A•m ¹2 was higher with PEG than without it. In the presence of PEG, the cathode potential polarized, the rate of hydrogen evolution increased, and the hydrolysis reaction of Zr 4+ and VO 2+ ions proceeded smoothly, resulting in an increase in the Zr and V content in the deposits. Additionally, the crystal platelets of Zn in the ZnZr and the ZnV oxide films became fine, and the surface coverage of the spongiform Zr and film-like V oxides increased. Furthermore, the corrosion current densities of the ZnZr and ZnV oxide films obtained from the solution with PEG were lower than those from the solution without it. The reduction rate of dissolved oxygen decreased in the films in the presence of PEG, thereby leading to a decrease in the corrosion current density.