This study investigated the effects of simulated flue gas temperature and mercury inlet concentration on the mercury removal efficiency using activated carbon produced from oil palm empty fruit bunch (EFB) which is prepared using physical (steam) activation method. The elemental, proximate, porous structure and particle size were performed for the oil palm EFB activated carbon. At low temperature, performance of activated carbon showed a good potential for adsorption of mercury. However, as temperature increase from 90 to 180°C, the efficiency of mercury was found to be decreased from 92 to 64 %. When the inlet mercury concentration was increased, the mercury removal efficiency is increased from 55 to 98 %. It was observed that mercury removal was favoured at lower temperature, such as 30 and 90°C and higher mercury concentration, such as 0.192 ppm for virgin oil palm EFB activated carbon.