In this article, a simple solution strategy for the synthesis of spherical monodisperse Bi2O3 nanoparticles under low temperature is presented. In the procedure, well-crystallized Bi2O3 nanoparticles were directly precipitated from the Bi(NO3)(3) homogeneous solution in the presence of dispersant (PEG) under strong alkaline conditions. The as-synthesized Bi2O3 nanoparticles can be stable against aggregation for more than 6 months. XRD, TEM, FIFIR, UV-vis, and laser particle size analyzing equipment have been employed to characterize the Bi2O3 nanoparticles. Preparative parameters, such as concentration of Bi(NO3)(3) and dispersant, reaction temperature, and reaction time were optimized to obtain Bi2O3 nanomaterials with considerable yield, uniform shape and narrow size distributions. (c) 2005 Elsevier B.V. All rights reserved.