Three adsorption equations were applied to verify the influence of correction values (CV) on adsorption parameters calculated using Langmuir, Freundlich and Gunary isotherms. It was found that the inclusion or not of the correction values into the -Langmuir equation did not yield appreciable differences either for amax or b parameters in the case of soils with relatively high organic matter content, cation exchange capacity and neutral pH. For the Freundlich equation, the higher the correction values the lower the partition parameters. Maximum adsorption parameters (amax ) calculated from the Gunary equation were proportionally related to correction values. The higher the correction values the higher the amax parameters. On the basis of the current results it seemed that the goodness-of-fit criteria for analytical data to adsorption equations herein applied may be partially related to correction values. Ideally, the sorption studies would be determined in systems in which the surface would be free of the adsorbate ion. Usually this restriction is far not feasible, mainly in soil environment.