Magnetic mesoporous particles were synthesized and their magnetic and structural properties are reported. The synthesis procedure consists of four steps: (i) preparation of magnetite colloidal nanoparticles; (ii) growth of a silica layer; (iii) development of the mesoporous structure and (iv) template removal. Two different methods for the template removal were studied and their effectiveness was discussed. Magnetization and Mossbauer spectroscopy measurements showed superparamagnetic behavior for the particles at room temperature. X-ray diffraction and nitrogen adsorption measurements showed a mesoporous MCM-41 structure with 2.48 nm pore diameter and 1023 m(2)/g total area. (C) 2009 Elsevier Inc. All rights reserved.