Kevlar [poly (p-phenilylene terephtalamide)], was used as a precursor in the preparation of acti-vated carbon fibers. For this intention, physical and chemical activations were carried out. Activated fiberswere physically prepared from the carbonization of the Kevlar and its later activation with CO 2 and steam ofwater, by the other hand; the chemically activated fibers were obtained by means of the impregnation of thematerial with phosphoric acid and their later carbonization. Different conditions were used and preliminaryanalyses of the precursor were taken into account (TGA-DTA / IR). The resulting fibers were characterizedby N 2 (77K) adsorption, infrared spectroscopy, SEM, and immersion calorimetry. Yields and Burn off werealso evaluated. The results shows that if you want to synthesize activated carbon fibers from Kevlar strongconditions respect to the commonly used such as water steam, high phosphoric acid concentrations and meth-ods of impregnation are the ones who allows the development of optimal surface areas and pore volumes.