The present investigation was undertaken to study the effects of temperature on adsorption-desorption of isoproturon on a clay soil and fit the data obtained to Freundlich adsorption-desorption isotherm model. The adsorption curves revealed that adsorption of isoproturon conformed to a L-type adsorption isotherm at the higher temperature (20"C), while a S-type at lower temperature (I OUC). The adsorption of isoproturon decreased with the increase in temperature, indicating the exothermic nature of adsorption :·eactions. The phenomenon of hysteresis appeared to be more pronounced at lower temperature than at higher temperature.