Superparamagnetic polymeric nanofibers were produced via an electrospinning technique from colloidally-stable suspensions of magnetite nanoparticles in polyethylene oxide and polyvinyl alcohol solutions. The magnetite nanoparticles were aligned in columns parallel to the fiber axis direction within the fiber by the electrospinning process. The polymer/magnetite nanofibers exhibited superparamagnetic behavior at room temperature, and deflected in the presence of an applied magnetic field. The mechanical properties of the nanofibers were maintained or improved after incorporating the magnetite nanoparticles. (C) 2004 Elsevier Ltd. All rights reserved.