High modulus and high tenacity polypropylene filament has been prepared by drawing as-spun filament on a heater having a gradient of temperature. The fiber properties are significantly affected by gradient heater settings, that is, nature and extent of gradient and end temperatures. Very high draw ratios are obtained through gradient drawing, resulting in high crystal perfection and crystallinity, along with very low void fraction. The gradient-drawn filaments showed superior mechanical as well as thermal properties when compared to filaments drawn over a constant temperature heater. Fibers having initial modulus of 17.5 GPa and tenacity of 750 MPa have been prepared in the process. Very low shrinkage of 7% at 150°C indicates excellent thermal stability of the gradient-drawn filaments.