In the conditioning tasks of olive-tree a large amount of a woody residue is generated. Such a residue has been traditionally used as a domestic fuel. In the last decades, however, this kind of use has lost importance and the preparation of activated carbons from olive-tree wood appears as an attractive alternative to valorize this by-product. In this study, the optimization of the chemical activation method with phosphoric acid for the production of activated carbon has been analyzed. The results obtained clearly show that samples prepared at 350 and 400 degrees C exhibit a discrete porous development. On the contrary, when the carbonization temperature increases above 450 degrees C the presence of a well-developed mesoporosity is observed. The mercury intrusion curves indicate that the samples exhibit a noticeably developed mesopore volume as well as a wide variety of mesopores ranging from 40 up to 1100 angstrom of diameter. If the appropriate conditions are used, it is possible to prepare activated carbons showing tailored properties in terms of micro- or mesoporous texture and surface area. (C) 2010 Elsevier B.V. All rights reserved.