A solvothermal process has been applied for the preparation of monodisperse magnetite by the decomposition of chelate iron alkoxide complexes with diethylene glycol. The magnetite nanocrystals have narrow size distribution and high crystallinity. The Fe3O4 products are characterized by X-ray diffraction and transmission electron microscopy, Mossbauer spectra and vibrating sample magnetometer (VSM). The nanoscale (similar to 50 nm) Fe3O4 powder obtained at 230 degrees C for 6 h possessed a saturation magnetization of 86.6 emu g(-1), a little lower than that of the correspondent bulk Fe3O4 (92 emu g(-1)). It is suggested that the high-crystallized Fe3O4 nanocrystals formed under appropriate solvothermal conditions should be responsible for the increased saturation magnetization in the nanosized Fe3O4. (C) 2008 Elsevier B.V. All rights reserved.