Surface coating of montmorillonite-based filler clay with stearic and oleic (9-octadecenoic acid) acids was presented. Sedimentation measurements showed that the sedimentation rate and the sediment volume decreased sharply with the adsorbed amount of the acid up to a certain concentration and then became constant. The chemical analysis showed that the adsorbed amount of either acid by montmorillonite clay increased with the equilibrium concentration of the acid in the solution. The adsorption isotherm indicated the formation of a monolayer on the clay surface at a lower concentration of the acids followed by formation of multilayers of the acids on the clay surfaces at higher concentrations. XRD analysis indicated no intercalation of either acid in the lamella of the clay. We concluded the possibility of surface coating of montmorillonite clay with a monolayer of fatty acids that render the clay organophilic. The adsorption of either acid improved the dispersibility of the clay particles in organic or polymeric media.