Adsorbent prepared from fly ash obtained from a thermal power plant was successfully used to remove cresol from an aqueous solution in a batch reactor. The adsorbent was characterized, and significant. removal of cresol was achieved. The adsorption isotherms were evaluated and the effects of system parameters, e.g., stirrer. speed and temperature on the adsorption, were studied. A theoretical model was proposed, and it was solved by using a quasi-steady-state approach. The intraparticle diffusivity was evaluated from one set of experimental data and was subsequently used to predict the change in bulk concentration with time for other experimental conditions. The predicted and the experimental results are in close agreement. The performance of the adsorbent prepared. was favorably compared with that of commercially available activated carbon.