In this study, the original interstratified kaolinite/ilite clay sample has been collected from altered basalt in Minas Gerais state, Southeast of Brazil. The natural sample was used in the intercalation process with dimethyl sulfoxide. The efficiency of the natural and modified kaolinite/illite clay in the adsorption of methylene blue was investigated by determining their equilibrium adsorption isotherms at dye concentrations and pH. The phyllosilicate sample and hybrid material were characterized by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The Freundlich expression for adsorption isotherm was applied in order to determine the adsorption capacity to form a monolayer and the constant related to the adsorption intensity. The maximum number of moles adsorbed was determined to be 55.0 and 62.5 mgg-1 for systems methylene blue/kaolinite/ilite and methylene blue / kaolinite/ilite + dimethyl sulfoxide, respectively.