Adsorption of Methylene blue on activated carbon obtained from Rice husk has been investigated by batch adsorption method. The percentage removal of dye has been optimized by studying the initial concentration of the dye, adsorbent dosage, adsorption time and pH. The highly porous activated carbon removed about 66% of the dye. The experimental data were found to be well fitted to Langmuir isotherm. This indicated the monolayer adsorption of methylene blue on the adsorbent.