Nanocrystalline cerium oxide films with grain sizes as small as 6 nm are deposited by anodic deposition. Cyclic voltammetry studies of a series of complexing ligands indicate that formation constants below 1 x 10(3) and a solution pH between 7 and 10 are needed for CeO2 film formation. A mechanism is proposed for the deposition of polycrystalline CeO2 films by anodic deposition. (C) 2003 The Electrochemical Society.