Coal fly ash, a solid waste from thermal power stations was used to successfully remove 2,4-dimethyl phenol by adsorption from aqueous solutions. The rate of adsorption follows first order kinetics before attaining equilibrium. Both diffusional and kinetic resistances affect the rate of adsorption and their relative effects vary with operating temperatures. Equilibrium adsorption data satisfied both Langmuir and Freundlich isotherms.