Conducting polyaniline/V2O5 composites have been synthesized byan 'in situ' deposition technique using the fine-grade powder (average particle size of approximately 400 nm) of V2O5 in the polymerization reaction of aniline. The composite thus obtained is studied by physicochemical characterization techniques such as FTIR spectroscopy, thermal analysis, scanning electron microscopy, and X-ray photoelectron spectroscopy. In addition, the study of the charge transport mechanism reveals that the charge transport is mainly governed by the space charge effects in such a composite. A large hysterisis in the current-voltage (I-V) characteristics, which in turn depend on the composite formation (i.e. the amount of the V2O5 added), is also observed. (C) 2001 Elsevier Science Ltd. All rights reserved.