A raw montmorillonite (Mt) and two organo-montmorillonites (OMt) with different hexadecyltrimethyl-ammonium bromide (HDTMABr) was used to adsorb Cu2+. The Cu2+ adsorption isotherms were performed, and Langmuir, Freundlich and SIPS mathematical models were evaluated. According to the R2 term, the experimental data were appropriately described by SIPS models for all the samples.