This paper reports on an evaluation of the intrinsic kinetic parameters of the specific sorption of clavulanic acid (CA) by ion-exchange chromatography. The first step of this work was to determine the diffusivity of CA in the pores of a resin, using a model based on diffusion with instantaneous adsorption. However, the adsorption rate step was found to affect the adsorption process. A mathematical kinetic model for the adsorption and desorption of CA was, therefore, proposed considering both kinetics and diffusion. Intrinsic kinetic parameters were obtained using the same experimental data utilized in determining diffusivity. In this case, the adsorption rate was considered to be the. process-limiting factor. Tests were carried out in a 200 mL stirring tank, with the initial solution at pH = 7.0 and the temperature maintained at 10 degreesC. The results showed that both the reaction rate and mass-transfer limitation have to be taken into account in the analysis,of CA adsorption by ion-exchange resins.