Aligned nanotibrous nanocomposites of Nylon 6 and surface-modified multimalled carbon nanotubes (MWNTs) were successfully synthesized via electrospinning, using a rotating mandrel. Scanning electron microscopy (SEM), differential scanning calorimetry (DSC), X-ray diffraction (XRD), transmission electron microscopy (TEM) and dynamic mechanical analysis (DMA) were done to characterize the morphology and properties of the nanofibrous mats. DSC and XRD observations suggested the presence of MWNTs and the high speed take-up facilitated the transformation of Nylon 6 from gamma phase crystals to a mixture of alpha and gamma phase crystals. TEM and WAXD were used to characterize the nanotube and molecular orientations, respectively. The storage modulus of the fibers increased significantly although the concentration of MWNTs was relatively low (0.1 and 1.0 wt%). Thus the combination of carbon nanotubes and nanoscale processing results in structural and mechanical enhancements of Nylon 6. (c) 2006 Elsevier Ltd. All rights reserved.