Helical carbon nanofibers were synthesized by means of acetylene pyrolysis at 450 degrees C using Fe nanoparticles as catalyst. There is no need to modify the Fe nanoparticles by a chiral reagent. The carbon nanofibers generated are crystalline and symmetric, with the (110) plane of Fe particle being the mirror plane. There would be a change in the shape of the nanofibers if the temperature at the beginning or during the synthesis were altered. Compared to the helical carbon nanofibers reported elsewhere in the literature, our samples show higher magnetization.