Carboxylated multi-walled carbon nanotubes (MWCNTs-COOH)/poly(vinyl alcohol) (PVA) nanofiber mats were fabricated using electrospinning. Due to the hydrophilic and swelling properties of the nanofibers, a transparent film was generated by self-assembly when the nanofibers were immersed in water. The composite film with MWCNTs-COOH fraction 8.76 wt% exhibits electrical conductivity of 1.8 x 10(-4) S/cm, while maintaining 166.98 MPa tensile strength and 61% optical transmittance. The method reported here is simple and feasible for large scale production of CNTs based composite films. (C) 2014 Elsevier B.V. All rights reserved.