The investigation on the adsorption of metal from aqueous solution onto a biomass is important for several reasons. First, biomass has been widely used as an economical sorbent to remove heavy metals from industrial wastewater. Second, studies have shown that impregnation of metals onto a biomass helps improving thermal conversion of the biomass, for example, by reducing the yields of tar and char and thus enhancing the formation of syngas during biomass gasification. The produced metal-loaded char from thermal conversion of metal impregnated-biomass on the other hand, can be re-used as a catalyst for various reactions such as water-gas shift reaction. In this study, we examine the adsorption of Nickel from aqueous solution onto oil palm mesocarp fiber by varying important parameters such as pH and initial metal concentration. The kinetic study shows that the adsorption of Nickel follows the pseudo-second order kinetic model. Our study also reveals that Nickel disperses well into nano-size particles on the oil palm mesocarp fiber, suggesting the suitability for carrying out thermal conversion of Nickel-loaded oil palm mesocarp fiber in the future. The adsorption of Nickel is lower but sufficient enough to be used as catalyst in biomass thermochemical processes.