In this research the application of thermal analysis techniques (TG-DTA) to the characterization of bentonite samples is presented The thermal behavior of 4 bentonite samples was investigated using simultaneous thermogravimetry (TG/DTG) and differential thermal analysis (DTA) techniques. It was observed that all bentonite samples exhibit 2 weight loss events on heating. The first weight loss event corresponds to the loss of molecular water from the exchange layer whereas the second weight loss event corresponds to the dehydroxylation of the silicate lattice. It was also observed that in both weight loss regions (loss of molecular water from the exchange layer and dehydroxylation of the silicate lattice) higher peak temperatures were obtained as the heating rate is increased.