Chitosan is a biocompatible material that has been researched in many areas in recent years. As it can be obtained from renewable sources, has antimicrobial properties, is biocompatible, and has no toxic effect, chitosan is currently a widely-used material. The use of chitosan was investigated in different areas related to dentistry. Chitosan is used in the prevention of caries and wear, to increase the regeneration capability of the dentin pulp complex, in pulpotomy to accelerate osteogenesis in guided tissue regeneration due to its hemostatic property, and primarily to benefit from its antimicrobial activity by adding it to materials such as glass ionomer cement, calcium hydroxide, and adhesive systems. The aim of this review was to examine the areas of use of chitosan in dentistry, and to explain its antimicrobial activity in particular, and also its capability for regeneration of dental tissues.