This work evaluated the potential to use saw dust based bio char in the treatment of mercury contaminated gold tailings wastewater. A sample of saw dust was first pyrolysed to produce bio char at 250 ◦ for 30 minutes. The bio char was then ground to particle size of 0.5 mm so as to enhance the bio adsorption properties as well as to increase the surface area. The bio char which had a surface area of 500-700 m²/g was put in contact with the wastewater for 40 hours noting the change in mercury content using AAS. The variation in mercury content was noted for changing pH. of 4-8 and bio char loading of 2-6 g/L. Highest mercury removal of >90% were noted at pH. of 8 and bio char loading of 6 g/L. From the study it can be concluded that saw dust based bio char provides an adsorbent that can lower mercury content in gold tailings wastewater