Clay-aromatic interactions have been investigated to assess the use of modified (organophilic) bentonite for binding benzene, toluene, ethylbenzene, and o-xylene (BTEX compounds) in contaminated liquids. Sorption isotherm and column leach tests were carried out to assess the efficiency of the clay in removing organics from liquid solutions, and X-ray diffraction analyses were performed to assess the changes in the basal spacing of bentonite as a result of its interaction with the organic compounds. This investigation indicates increases in the basal spacing of the modified bentonite as a result of the interaction between the clay and organics. In addition, the sorption isotherm and column leach test results revealed that the modified bentonite samples effectively removed benzene, toluene, ethylbenzene, and o-xylene from liquid solutions. The efficiencies of the clays in removing BTEX compounds were 75%, 87%, 89%, and 89%, respectively, suggesting that the modified bentonite can be used as a practical organic adsorbent for waste water treatment systems, landfill liners, slurry walls, and underground storage tanks＇ barriers.