Magnetite nanorods were successfully synthesized from ferric chloride (FeCl3) and diamine hydrate ((H4N2H2O)-H-.) reagents via a simple, mild reduction-oxidization hydrothermal process in the presence of polyethylene glycol. The magnetite nanorods were characterized by X-ray diffraction, Mossbauer spectroscopy, and magnetization measurements. The nanorods exhibit a ferromagnetic behavior with a high saturation magnetization (90.5 emu/g), a little lower than that of the corresponding bulk material (92 emu/g). The mechanism for the improved magnetic properties of the magnetite nanorods is discussed based on the oriented growth of particles. (C) 2004 Elsevier B.V. All rights reserved.