To obtain activated carbons from chestnut tree wood, we followed a two-step process consisting, basically, of a carbonization stage at different temperatures (250 degrees C, 350 degrees C, 450 degrees C, 550 degrees C, 650 degrees C, 750 degrees C and 850 degrees C) followed by an activation stage with phosphoric acid. Then, we characterized the resulting charand activated carbon through chemical analysis, physical adsorption of gases (N-2 at 77 K), mercury porosimetry, and densities by helium and mercury displacement. The overall conclusion obtained in this work was that carbonization and chemical activation with phosphoric acid produce activated carbons with fairly good textural properties. The effect of chemical activation on char is reflected in the important development of porosity caused by treatment with phosphoric acid.