In this study, the effect of interlayer d-spacing on the contact angle (theta(c)) of montmorillonite nanoclays was investigated. Three type of montmorillonites, pure hydrophilic, modified with 35-45 wt.% dimethyl dialkyl (C14-C18) amine (Nanomer I.44P) and modified with (1-hexadecyl) tri-methylammoniumbromide (HDTMAB), were used for comparison. According to the results, it was found that cations can be replaced by organic cations and interlayer spacing increases. Although organophilic montmorillonite clays whose surface energy is lowered and is more compatible with organic polymers, they shows hydrophobic behavior with water. Modified clays were found to have a larger interlayer d-spacing and also a larger time-independent contact angle in comparison to the un-modified clay.