Conducting nanofibers composed of poly(methyl methacrylate) (PMMA) and poly(3,4-ethylenedi oxythiophene) (PEDOT) were fabricated by a dual process using the electrospinning (ES) and oxidative polymerization (OP) methods. PMMA nanofibers containing the EDOT monomer were prepared by electrospinning a PMMA and EDOT monomer mixture onto an oxidant solution. The final products, PEDOT-coated PMMA nanofibers, were synthesized during the OP process; EDOT monomer-swollen PMMA nanofibers provided a stable template for the growth of the thin PEDOT layer. The morphology of the PEDOT-coated PMMA nanofibers was analyzed using scanning electron microscopy and transmission electron microscopy. The growth mechanism of the EDOT monomer on the electrospun PMMA nanofibers was monitored using Fourier transform infrared spectroscopy. In addition, the conductivity of the PEDOT-coated PMMA nanofiber mats was measured by the van der Pauw method. The PEDOT-coated PMMA nanofiber mats prepared in this study exhibited good electrical properties and are expected to be excellent candidates for the fabrication of flexible electronic devices such as thermoelectric devices, gas sensors, and energy-storage systems. (C) 2013 Elsevier Ltd. All rights reserved.