Abstract: The invention relates to a colloidal dispersion, characterized in that it comprises a cerium oxide and at least one additive chosen from .beta.-diketones, monocarboxylic acids containing a hydroxyl function in the .alpha.- or .beta.-position and diols. It also relates to a redispersible composition in the form of a colloidal dispersion based on cerium oxide and the same above mentioned additives. The colloidal dispersion of the invention can be obtained by a process which is characterized in that at least one above mentioned additive is added to a colloidal dispersion of cerium oxide as the starting material. Finally, the invention relates to the use of a dispersion of the above type or of the type obtained by redispersing a redispersible composition, on a substrate as an anticorrosion agent, in a cosmetics composition, in catalysis, in particular for automobile post-combustion, in lubrication or in ceramics.