Three activated carbon samples have been prepared by thermal (AC(char)), physical (with CO2, AC(co2)) and chemical (with KOH, AC(KOH)) activation of waste cork powder. Cork was characterized by thermogravimetric, elemental and proximate analyses, and activated carbons were characterized by elemental and proximate analyses, adsorption-desorption of N-2, acid/base and Boehm's titration and FTIR (ATR) spectroscopy. A commercial activated carbon sample (AC(com)) was subjected to the same characterization program for comparison purposes. Activation of cork conducted to an increase in BET surface area and pore volume in the sequence: AC(char) < AC(CO2) < AC(KOH). getting close to those of A(com), and to an increase in surface acidity in the sequence: AC(char) < AC(co2) approximate to AC(com) < AC(KOH). The four adsorbents were tested in the adsorption of SO2, where AC(KOH) presented the highest adsorption capacity, while AC(char) and AC(co2) presented similar behaviors, comparable to that of AC(com). Adsorption equilibrium was successfully fitted to Langmuir and Freundlich isotherms. Desorption experiments demonstrated how SO2 strong adsorption was favored when decreasing surface acidity. (C) 2012 Elsevier B.V. All rights reserved.