In this paper, the preparation of activated carbons from extracted-oil palm fibers for the reduction of nitric oxide was studied. Preparation methods included two-Step CO2 activation, one-step CO2 activation and chemical activation with KOH impregnation. The effects of the heating temperature and hold time on the properties of the chars and activated carbons were investigated. For chemical activation, the effects of KOH concentration and soak; time were also studied. The activated carbon with the highest BET surface area was obtained by pyrolysis at 750 degrees C for 2 h and subsequent activation with CO2 at 850 degrees C for 30 min for extracted-oil palm fibers impregnated with 0.10 M KOH for 24 h. Experimental results from the thermogravimetric study on the reduction of nitric oxide showed that activated carbons prepared from extracted-oil palm fibers could reduce NOx appreciably either by reaction with NO at high temperatures or by simultaneous reaction and adsorption for a mixture of NO and O-2. These activated carbons can be potentially used for NOx reduction in flue-gas streams from high-temperature combustors or downstream of electrostatic precipitators and in some chemical plants operating at room temperature.