The interaction between alkyd resins and kaolinte has been studied by means of adsorption measurements and spectroscopic methods such as electron spectroscopy for chemical analysis (ESCA) and diffuse reflectance infrared Fourier transform spectroscopy. The interaction is mainly governed by Lewis acid-base interactions but the molecular weight distribution and the oil length of the alkyds are of great importance. The kaolinite surface appears to be amphoteric since both acidic and basic species are adsorbed. The alkyd resins are very polydisperse. The experimental results are in agreement with the prediction of the theory of Cohen Stuart et al. (M.A Cohen Stuart, J.M.H.M. Scheutjens and G.J. Fleer, J. Polym. Sci., Polym. Phys. Ed., 18(1980) 559) for adsorption of polydisperse polymers. The alkyds are strongly adsorbed on the kaolinite, but not aluminium or hydroxxyl groups next to the aluminium. Double bonds, orginationg from the fatty acid part of the alkyd, play an active role in the adsorption process. The adsorption is only slightly affected by the temperature.