Biopolymers are polymers that are produced from living organisms or synthesized artificially from biological source materials. They are generally polymers of starch. These are composed of manomeric units and degraded naturally in the environment, without any toxic effect on environment hence they are environment friendly. There are three main classes of biopolymers, according to the composition of monomers used and the structure of biopolymer formed: polynucleotides, polypeptides and polysaccharides. In recent past plant disease management was carried out by using hazardous chemical pesticides. Keeping in view of human health and environment, recently much attention was paying towards use of biodegradable and environment friendly plant disease management. It is interesting to know that biopolymers having antimicrobial properties and it can be utilized in management of diseases caused by fungi, bacteria, virus and nematodes. These biopolymers are renewable composed of plant material which can be grown endlessly. Most commonly used polymers are derivatives of polysaccharides (chitosan, cellulose, starch and polyactic acid). The chitosan (CHT) biopolymer is a de-acetylated chitin derivative that exists in the outer shell of shrimp, shellfish, lobster or crabs, as well as fungal cell walls. Because of its biodegradability, environmental non-toxicity, and biocompatibility, it is an ideal resource for sustainable agriculture. This article focuses in detail about role chitosan biopolymer in plant growth promotion and plant disease management.