Water pollution by toxic organic Compounds is of concern and the demand for effective adsorbents for the removal of toxic compounds is increasing. Present work deals with the adsorption of phenol (PhOH) and o-chlorophenol (o-CP) on mesoporous MCM-41 material. The effect of surfactant template in MCM-41 on the removal of PhOH and o-CP was investigated. The comparison of adsorption of PhOH and o-CP on uncalcined MCM-41 (noted as MCM-41) and calcined MCM-41 (noted as C-MCM-41) was investigated. It was found that MCM-41 shows significant adsorption for PhOH and o-CP as compared to C-MCM-41, this may be because of the hydrophobicity created by surfactant template in the MCM-41. Batch adsorption studies were carried out to study the effect of various parameters like adsorbent dose, pH, initial concentration and the presence of co-existing ions. It was found that adsorption of PhOH and o-CP depends upon the solution pH as well as co-existing ions present in the aqueous solution.The equilibrium adsorption data for PhOH and o-CP was analyzed by using Freundlich adsorption isotherm model. From the sorption studies it was observed that the uptake of o-CP was higher than PhOH. (C) 2008 Elsevier B.V. All rights reserved.