Indium tin oxide (ITO) nanofibers were successfully prepared via an electrospinning method, followed by annealing at 400 C. Mixed solutions of ITO nanoparticle sol and polyethylene oxide (PEO) were used as precursors of the nanofibers. The PEO decomposed during annealing to yield ITO fibers. The fibers were characterized by scanning electron microscopy (SEM), x-ray diffraction (XRD), thermo-gravimetric/differential thermal analysis (TG/DTA), UV–vis spectrophotometry and four-probe resistivity measurements. The diameter of the prepared fibers was controlled by adjusting the flow rate and the applied electric current. In 2 O 3 crystallized in the ITO nanofibers with a crystallite size of 27 nm. The optical transmittance in the visible region approached 90% in films deposited for 5 min, confirming that the nanofiber film is still transparent in the optical region. The sheet resistance of the nanofiber film was linearly dependent on the inverse of the deposition time and on the PEO/ITO ratio.