Polyvinylidene fluoride (PVDF) fibers with a high amount of β phase crystal structure were prepared by melt spinning. With this technique, the cold drawing process is critical and efficient when aiming for a high amount of β phase. During the cold drawing process, more than 80% of the originally formed α phase crystal structure was converted into the β phase structure. In addition, the incorporation of 0.01 wt % of amino-modified double wall carbon nanotube (NH2-DWCNT) could further enhance the β phase content in the PVDF fibers. FTIR and DSC studies showed that the addition of NH2-DWCNT to PVDF fibers could increase both the total crystallinity and β phase fraction in PVDF. The addition of nanoclay was found to be less efficient in this respect.