Hyaluronic acid is a carbohydrate, more specifically a mucopolysaccharide, occuring in all living organisms. It is found primarily in the extracellular matrix and its functions in human body are numerous. Over 80 years have passed since the discovery of hyaluronic acid, when Meyer and Palmer extracted it from bovine vitreous humor. It is a linear polymer of exceptional molecular weight and is synthesized in the cellular plasma membrane with help of plasma membrane proteins HAS1, HAS2 and HAS3. Except vertebrates, hyaluronic acid is also found in some bacteria and viruses. Hyaluronic acid may be found in saliva, gingival crevicular fluid and the periodontium. In periodontology it has been used as monotherapy or as adjunct to non-surgical and/or surgical periodontal treatment. Therapy of gingivitis and periodontitis has yielded better results if mechanical therapy was combined with hyaluronic acid which controls inflammation, reduces gingival bleeding and has a bacteriostatic effect.Hyaluronic acid may also be used in interdental papilla loss treatment instead of an operation. Combination of hyaluronic acid, hydroxyapatite and beta tricalcium phosphate has very good effects in osteoconduction and preservation of alveolar sockets. Hyaluronic acid plays an important role in wound healing where it acts on the expression of fibroblasts, stimulates synthesis of collagen and adhesion and cell proliferation. Dental implants coated with hyaluronic acid have good primary osteointegration.