Studies on the removal of mercury(II) ions by adsorption onto indigenously prepared dates nut (DC) and commercial activated carbons (CAC) have been carried out with an aim to obtain data for treating effluents from metal processing and chloralkali industries. The effect of various process parameters has been investigated by following the batch adsorption technique at 30 +/- 1 degrees C. The percentage removal of mercury(II) ions increased with the decrease in initial concentration and increase in contact time and dose of adsorbent. As initial pH of the slurry increased, the percentage removal increased and reached a maximum value. The process parameters were optimised. Adsorption data were modeled with the Freundlich and Langmuir isotherms, the first order kinetic equations proposed by Lagergren and Bhatacharya and Venkobachar and Weber-Morri's intra-particle diffusion model and the equations models were found to be applicable. The kinetics of adsorption is observed to be first order with intra-particle diffusion as one of the rate determining steps. Removal of mercury(II) ions by DC and CAC is found to be favourable and hence DC could be employed as an alternative low-cost adsorbent for effluent treatment, especially for the removal of mercury(II) and other metal ions.