Crystalline ceria (CeO2) nanoparticles have been successfully synthesized by a simple and fast microwave-hydrothermal method at 130 degrees C for 20 min. As-synthesized CeO2 powders were calcinated at 500 degrees C for 1, 2 and 4 h. The products were characterized by thermogravimetric analysis (TG-DTA), X-ray powder diffraction (XRD), field-emission scanning electron microscopy/STEM mode (FEG/STEM), Fourier Transformed-IR and RAMAN spectroscopies. It is shown that synthesized ceria powders have a spherical shape with particle size below 10 nm, a narrow distribution and exhibit weak agglomeration. The FTIR spectrum of the ceria exhibits strong broad band below 700 cm(-1) which is due to the delta (Ce-O-C) mode. Raman spectrum is characterized by the presence of a very strong band to 464.5 cm(-1). The microwave-hydrothermal method enabled cerium compounds to be synthesized at low temperature and shorter time. (C) 2008 Elsevier B.V. All rights reserved.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)