Color of water is the first indicator of contamination. It is, therefore, necessary to remove contaminants from wastewater before discharging it into water bodies as these are harmful, especially to aquatic life. Dyes from wastewater of textile and dying industries are currently one of the environmental problems, wherein increased concentration of these pollutants poses environmental water degradation. Using adsorption, this study tested the effectiveness of Coconut lumber sawdust, an indigenous waste product, as biosorbent in an artificially prepared methylene blue (MB) dye wastewater. The effect of the different initial concentration was also studied. Coconut lumber sawdust was treated with 0.01 M potassium hydroxide (KOH) and was activated at 1800C for two hours in an oven. The adsorption process included agitation through aeration. Filtered samples were analyzed using Perkin Elmer Lambda 40 UV-Vis spectrophotometer with the maximum wavelength of 665 nm. Results showed that the percent removal of MB using coconut lumber sawdust ranges from 68% to 81% that implies that coconut lumber sawdust is an effective biosorbent of MB. The equilibrium loading was found to increase as the initial concentration increases. The adsorption of MB is primarily because of the activation of the sawdust. During activation, the internal surface of the coconut lumber sawdust becomes more highly developed and extended by controlled oxidation of carbon atoms (Cameron Carbon Inc., 2009). Accessibility of the internal surface area is due to the network of pores opened as the coconut lumber sawdust was activated.