The metallic ion removals have been studied by several researchers in the recent years. Activated carbons have been often used in metallic ions adsorption processes due their large available surface area, besides being cheap and environmentally friendly material with good cost-benefit for the industries. The present work evaluated the simultaneous adsorption of the metallic ions Cd(II), Cu(II) and Cr(VI) on activated carbons from different origins (vegetal and mineral) by using a fractional factorial design 2(5-1) The main and interactive factors studied were the initial concentration of metallic ions, pH, temperature, type of activated carbon and contact time. The resulting models were different for each ion. The main influent factors were the initial concentration of metal, pH and activated carbon type. The Cr(VI) adsorption was better than Cu(II) and Cd(II) at pH 2. In this condition, the vegetal activated carbon from coconut shell (DEN). Elais guineensis, was better than mineral bituminous activated carbon (MBE) for Cr(VI) adsorption. At pH 4. Cu(II) was removed in bigger quantities, especially by MBE. Cu(II) was the main metallic ion removed at pH 4. The removal of Cd(II) was efficient only at pH 4 and the mineral bituminous activated carbon showed the best performance. The variance analysis (ANOVA) was applied in the fractional factorial design and the statistic data showed adequate models. (C) 2010 Elsevier B.V. All rights reserved.