High Modulus high tenacity polypropylene filaments have been prepared by drawing them on a heater with a gradient of temperature. The thermal properties have been analyzed, and the effects of nature of the gradient and end temperatures on thermal properties of the filament have been investigated for such filaments. Low shrinkage values even at 150 degrees C, high retention of storage modulus in dynamic mechanical analyses and very low change in length in thermomechanical analyses have been the characteristic of the gradient drawn filaments. The filaments have high crystallinity, crystal perfection, and crystal orientation. In addition, the reported process has the advantage of being continuous in nature. (c) 2006 Wiley Periodicals, Inc.