The partial gasification of Eucalyptus globulus charcoal, using carbon dioxide and steam as activating agents is studied. The influence of some preparation variables such as temperature and reaction time on textural, morphological and acid-base properties are given. The results obtained show that both activating agents produce microporous activated carbons and that a large increase in meso- and macroporosity is observed when steam and high burn-off are used. It has been found that these activated carbons have weak acid sites and the effect of the burn-off on the acid strength depends on the activating agent. Thus, the acid strength of these sites decreases with the burn-off when steam is used, but no effect is observed when carbon dioxide is used.