Three physico-chemical characteristics of Acacia activated charcoals were determined: the degree of activation, the specific surface and surface functions. The coals are prepared from Acacia auriculaeformis and Acacia mangium, leguminous and fast growing trees, available in Côte d’Ivoire. They were activated by chemical means, by impregnation with phosphoric acid (H3PO4). Analysis of the results indicates that the activation yields are below 50% for both types of coal. In addition, the activated carbon-based Acacia auriculaeformis has a larger surface area than that based Acacia mangium. The two activated coals have mixed surface functions, predominantly acid, which give them a dual reactivity for both anionic and cationic adsorbates.