During the past decade, isothermal titration calorimetry ( ITC) has developed from a specialist method to a major, commercially available tool in the arsenal directed at understanding molecular interactions. At present, ITC is used to study all types of binding reactions, including protein-protein, protein-ligand, DNA-drug, DNA-protein, receptor-target, and enzyme kinetics, and it is becoming the method of choice for the determination of the thermodynamic parameters associated with the structure transformation of one molecule or non-covalent interaction of two ( or more) molecules. Here, the new applications of ITC in protein folding/unfolding and misfolding, as well as its traditional application in molecular interaction/recognition are reviewed, providing an overview of what can be achieved in these fields using this method and what developments are likely to occur in the near future.