The adsorption capacity of two low-cost adsorbents, Oryza sativa L. husk and chitosan, was studied. Lead solution was used as the adsorbate. The effect of initial lead concentration, pH, temperature, weight of adsorbent, particle size and contact time on lead uptake was investigated. It was found that the isotherm data were well described by the Freundlich isotherm. for both adsorbents. The adsorption capacities of rice husk and chitosan were 5.69 and 8.31 mg g(-1), respectively. It was shown that chitosan was more effective than rice husk. (c) 2005 Society of Chemical Industry.