Summary: Dark chocolate stands out as a functional food, due to the large amount of cocoa solids, which is rich in saturated fatty acids and antioxidant compounds. Thermoanalytical techniques such as thermogravimetry (TG) allows to follow in detail the changes in the substance mass during heating, which is possible to establish the temperature range when the sample begins to decompose. Thus, this study aimed to compare the thermal stability of different dark varietal chocolates by thermogravimetry. In order to characterize the different kinds of dark chocolate, three samples of chocolates containing 70% of the cocoa mass were analyzed. They were Pará-Parazinho, Ipiranga I and PS1319 cultivars. The analytical curves were obtained from Perkin Elmer thermogravimetric equipment (TG), model - Pyris 1 TGA, previously calibrated. It was weighed 10mg of chocolate in alumina pot, with heating ratio of 10ºC per min-1, and temperature ranged from 25 to 700ºC. The samples have a similar thermogravimetric profile, presenting two stages of decomposition, the first one characterized by an endothermic event, caused by dehydration at maximum decomposition temperature of 250ºC. In studies with commercial chocolates, the maximum temperature of decomposition was around 220ºC. The second event occurred at a temperature around 450ºC, indicating the loss of mass and decomposition of the triglycerides and other constituents, identified as an exothermic event, where the loss of mass corresponded to 84% in averageIn. the final decomposition temperatures the loss of the nutritional value begins in chocolates, caused by the combustion process. The tests showed that there was no difference in the thermal profile between the samples and that thermogravimetry provides important information about the stability and thermal transitions of the chocolates.