High-purity Pr(OH)(3) nanorods with uniform diameter were synthesized in large scale by microwave-assisted heating method, and Pr6O11 nanorods were obtained by subsequent thermal decomposition of the as-prepared Pr(OH)(3) nanorods at 500 degrees C for 6h. The products were characterized by X-ray powder diffraction (XRD), transmission electron microscopy (TEM), and high-resolution transmission electron microscopy (HRTEM). It was found that the hydroxide nanorods with hexagonal phase and oxide nanorods with cubic phase have high crystallinity and purity. The influences of the KOH concentration and microwave heating time on the size and morphologies of Pr(OH)3 nanorods were discussed. The mechanism for the formation of Pr(OH)3 nanorods under microwave heating process was preliminarily proposed. (C) 2007 Published by Elsevier B.V.