We report on the observation of field-effect transistor (FET) behavior in electrospun camphorsulfonic-acid-doped polyaniline/polyethylene oxide (PEO) nanofibers. Saturation channel currents are observed at surprisingly low source-drain voltages. The hole mobility in the depletion regime is 1.4x10(-4) cm(2)/V s, while the one-dimensional (1-D) charge density (at zero gate bias) is calculated to be approximately 1 hole per 50 two-ring repeat units of polyaniline, consistent with the rather high channel conductivity (similar to10(-3) S/cm). Reducing or eliminating the PEO content in the fiber is expected to enhance device parameters. Electrospinning is thus proposed as a simple method of fabricating one-dimensional polymer FETs. (C) 2003 American Institute of Physics.