Trace element selenium and its metabolites have received a great deal of attention with regard to the development of new therapies for both cancer prevention and treatment. Following this approach, our research group has synthesized a series of novel selenocarbamates derivatives. We present thermal analysis of the novel compounds, performed with differential scanning calorimetry and thermogravimetric analysis. Relationship is found among thermal analytical data and structure of the different series of compounds. These data allow establishing criteria for the selection of substituents that improve the stability. The most thermally unstable compounds are those with higher cytotoxic activities, suggesting that the release of methylselenol could be implicated in the biological activity.