Crystallization behavior of melt-blended polypropylene (PP)/single wall carbon nanotube (SWNT) composites has been studied using optical microscopy and differential scanning calorimetry. Polypropylene containing 0.8 wt% SWNT exhibits faster crystallization rate as compared to pure polypropylene. PP/SWNT fibers have been spun using typical polypropylene melt spinning conditions. The PP crystallite orientation and the SAINT alignment in the fibers have been studied using X-ray diffraction and polarized Raman spectroscopy, respectively. (C) 2003 Elsevier Science Ltd. All rights reserved.