Thermoanalytical techniques are valuable tools for the characterization of thermosetting polymers. Examples are given of the application of thermal methods to the identification of filled and unfilled epoxy and amino resins. Various thermo-analytical methods of following the curing of thermosetting polymers are considered. Thermal techniques are essential to the study of degradation reactions; the decomposition of a melamine formaldehyde resin is discussed in detail. It is concluded that the usual methods of thermal analysis alone are insufficient to characterize fully the degradation of amino resins.