In this study, the adsorption potential of activated carbon olive stone for removal of Ni(II) ions from wastewater has been investigated. The study involves batch type experiments to investigate the effect of initial concentration, adsorbent dose, agitation speed, contact time, temperature and pH of solution on adsorption process and the optimum conditions were evaluated. The adsorption process has fit pseudo-second order kinetic models. Langmuir and Freundlichadsorption isotherm models were applied to analyze adsorption data and both were found to be applicable to this adsorption process. Thermodynamic parameters, e.g., ΔGº, ΔSº and ΔHº of the on-going adsorption process have also been calculated and the sorption process was found to be endothermic. Finally, it can be seen that activated carbon olive stone was found to be more effective for the removal of Ni(II) from waste water than any adsorbent was used.