Thermosensitive polymers are materials capable of undergoing a reversible phase transition in aqueous media in response to a variation of the temperature. They have attracted high scientific interest for advanced applications in diverse areas, such as biotechnology, biomedical, environmental, food industry and other fields. At the same time, chitosan is a promising marine polysaccharide that has long been used in applications such as drug, peptide or gene delivery systems. Being the most abundant marine polysaccharide, chitin and chitosan do not exhibit thermoresponsive properties, but some of their derivatives do. In the present chapter, the efforts to produce chitosan-based thermosensitive materials are reviewed. Particularly, the properties and applications of chitosan-glycerophosphate thermogelling system are examined; the methods of synthesis of chitosan copolymers grafted with poly(Nisopropylacrylamide) or poly(N-vinylcaprolactam), their physicochemical properties and most of their prominent applications are discussed as well.