The adsorption isotherms of nitrobenzene from aqueous solutions in the concentration range 20-200 mg/L have been studied on five different commercially available activated carbons with surface areas varying between 650-1300 m(2)/g. The adsorption depends upon surface area but is not linearly related to it. The adsorption isotherms on oxidised and degassed samples of activated carbons indicate that the adsorption increases on degassing but decreases on oxidation.