Lignin fibers with and without platinum were synthesized in a single step by electrospinning of lignin/ethanol/platinum acetyl acetonate and lignin/ethanol solutions, respectively. The fibers obtained were stabilized in air at low temperature to avoid fiber fusion during the subsequent carbonization process. The effect of the carbonization temperature (600–1000°C) on surface chemistry, morphology, textural properties, and oxidation resistance of the final carbon fibers was studied. The carbonization process decreased the oxygen content of the fibers, increasing the carbon and surface platinum proportion and producing a well developed microporous structure. Carbon fibers with and without platinum with apparent surface areas of 1178 and 1195m²/g, respectively, and micropore volumes of around 0.52cm³/g were obtained. The diameter of the carbon fibers obtained is in the range of 400nm to 1μm. Carbon fibers with surface platinum of 0.6% in weight were obtained. The carbon fibers with and without platinum showed high oxidation resistance despite their highly developed porous structure.