Electrically conductive composites containing polypropylene (PP) and polyaniline (PANI) were prepared using PP with three different melt flow rates (MFRs) and a commercial PANI-complex in proportions of 80% by weight and 20%, respectively. Composite blends were melt-spun to fibers under different solid-state draw ratios. Rheological studies of dynamic viscosity, as well as the storage modulus and loss modulus showed that the prepared PANI-complex/PP blends exhibit different dynamic rheological behavior, depending on the PP used. This confirms the blends' morphological differences. PP matrix viscosity was found to play an important role in the electrical properties of the prepared fibers. Fibers prepared using the matrix with the lowest viscosity, showed a larger dispersed phase size in the cross-sectional SEM micrographs, maximum conductivity observed at higher draw ratios and a more linear resistance-voltage relationship than those of the fibers prepared using the higher viscosity matrices. (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 119: 2800-2807, 2011