We demonstrate directional electromechanical properties of poly(3,4-ethylenedioxythiophene)/poly(4-styrene sulfonate) (PEDOT/PSS) composite films containing aligned poly(vinyl pyrrolidone)/poly(methyl methacrylate) nanofiber assemblies. The aligned nanofiber assemblies showed anisotropic wettability based on the high alignment degree of the nanofibers. The PEDOT/PSS composite film containing aligned nanofibers displayed an anisotropic actuation response when a voltage was applied in air. The orientation of the embedded nanofibers within the PEDOT/PSS matrix leads to the control of actuation direction because of the difference of anisotropic mechanical properties in the composite films. Polymer Journal (2011) 43, 849-854; doi: 10.1038/pj.2011.62; published online 27 July 2011