The adsorption of carbofuran on hydrogen, sodium, and calcium saturated soils has been studied at 25 and 50 degrees C. The adsorption data for all types of soils is in close agreement with Freundlich isotherms and yielded S-class isotherms. The maximum adsorption was observed in acid saturated soil. Therefore, it has been in accordance with the partial molal free energy changes (F) and Kd values. The adsorption has been lower at higher temperatures. The thermodynamic constant (KO), standard free energies (delta G degree), enthalpies (delta H degree), and entropy changes (delta S degree) have been calculated for predicting the nature of adsorption.