This review concerns recent research on the synthesis of cerium oxide (also known as ceria, CeO(2)) in colloidal dispersions media for obtaining high surface area catalyst materials. Nanoparticles as small as 5 nm and surface area as high as 250 m(2)/g can be readily prepared by this method. Both normal micelles and water-in-oil microemulsions have been employed to directly precipitate nanoceria or other cerium precursors which can be converted into ceria by calcination.