Surface energies of montmorillonite-alkylammonium complexes were determined from contact angle measurements performed using the two-liquid phase method. An apparent surface energy ?a (with),a= yP + yD) was determined for partially hydrated surfaces. When the length of the organic ion increases, that is to say when the part of the organic surface increases, ?s approaches values characteristic of low surface energy polymers. It was possible to correlate the variation of yP and yD with the nature of the surface, i.e. organic/mineral, hydrated/dry. At complete coverage of the mineral, the surface properties measured are the organic coating ones.