The organic intercalation of cationic smectite clays is achieved by using alkali salts of alkyl carboxylic acids, instead of using conventional quaternary ammonium salts as ionic exchanging agents. Various organic acid salts, such as CH3(CH2)(16)COO-Na+, can be incorporated into divalent montmorillonite (M2+-MMT) with a 30-40 wt.-% organic embedding and an X-ray diffraction basal spacing of 43 angstrom from the pristine 10 angstrom. The intercalation is generalized for carboxylate salts of different alkyl lengths and for alkali metal ions, including sodium and potassium ions, but is specific for the divalent MMT clay. This new type of organic species for clay modification allows the preparation of organoclays in the absence of quaternary ammonium salts. It is proposed that the organic embedding is driven by the formation of a thermodynamically stable RCOO-/M2+/SiO- complex.