Activated carbons were produced from olive bagasse and their characteristics were investigated. Olive bagasse was first carbonized at 500 degrees C in N-2 atmosphere. Then, the obtained chars were activated with steam. The effects of activation temperature and duration were examined. The resultant activated carbons were characterized by measuring their porosities and pore size distributions. The activated carbons produced had the BET surface areas ranging from 523 to 1106 m(2)/g. The total pore volume was increased from 0.2981 to 0.6067 cm(3)/g. Adsorption capacity was demonstrated by the iodine numbers. The surface chemical characteristics of activated carbons were determined by FTIR spectroscopic method and Boehm's titration method. The microstructure of the activated carbons prepared was examined by scanning electron microscopy (SEM). The experimental data was proved that the properties of activated carbons depend on the final temperature of the process and duration of treatment at the final temperature. (C) 2010 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.