The removal of organosulphur compounds (ORS) from diesel fuel is an important aspect of Jordanian's effort to reduce air pollution by sulphur oxides. The results of this work revealed that activated carbon (AC) has an excellent adsorption for the ORS from non-aqueous diesel medium. Experimental data revealed that percentage removal of the ORS was slightly affected with particle size of the adsorbent, which indicates that elimination of the ORS mainly occurred on the external surface area and the adsorption onto the pores of the adsorbent has a small effect on the entire elimination process. Removal of the ORS by the AC has an endothermic nature where percentage removal values were increased by temperature. The maximum percentage removal value was 72% which was reported at: 2.0 g, 300-500 mu m, 25 degrees C, and 3 days shaking. The experimental results were plotted and treated with Langmuir isotherm, uncommon isotherm shapes were obtained. Therefore, it was not fitted to the experimental results which might reflect a complex nature of adsorbing the ORS onto the AC. However, this behaviour gives an indication on the complex adsorption mechanisms. Finally, the mode of interaction between the ORS and the AC was characterised by comparing the changes in the position and intensity of the surface functional groups using FTIR technique. (C) 2010 Elsevier B.V. All rights reserved.