A new strategy is employed for the preparation of hybrid nanocomposites based on silanized magnetite nanoparticles (MNPs-Si) and sulfonated polyanilines (SPAN). The method involves chemical oxidative copolymerization of orthoanilinic (OA) or metanilinic (MA) acid with aniline (ANI) in the presence of MNPs-Si. The nanocomposites, MNPs-Si/SPAN (OA/MA), were characterized for morphology and structural, thermal, electrical and magnetic properties. The composites have higher conductivities (0.25-0.39 S/cm) in comparison to pristine PANI (5.19 x 10(-3) S/cm). The nanocomposites exhibit superparamagnetism. (c) 2007 Elsevier Ltd. All rights reserved.