Carbonaceous adsorbents were obtained from waste tires and used for adsorption of nitrogen dioxide. The adsorbents were obtained by pyrolysis of waste tires followed by chemical (KOH) and physical (CO2) activation at 550 and 800 degrees C. The surface structure and chemistry of the adsorbents obtained were analyzed. Strong influence of modification processes on both textural and acid-base properties of the adsorbents obtained was found. The adsorbents with the most developed surface area were those subjected to chemical activation. Higher temperature of the process was found to improve the textural properties as well as acid-base properties of the material obtained more than the lower one. Furthermore, the effect of modification conditions, e.g. pyrolysis as well as chemical or physical activation, on the performance of waste tires based materials as adsorbents of NO2 at room temperature and dry conditions was investigated. The results indicate that sorption capacity strongly depends on the modification process (pyrolysis or activation). The surface sites present on the adsorbent surface can include reactive centers, which can also be generated as a result of exposure to NO2. The surface properties are the major determinant of adsorption capacities. (C) 2011 Elsevier B.V. All rights reserved.