Cyclooxygenase (COX) is an enzyme that is responsible for formation of important biological mediators called prostanoids, including prostaglandins, prostacyclin and thromboxane. Constituting a key regulatory enzyme of the ecosanoid biosynthetic pathway, COX catalyzes the conversion of arachidonic acid to protaglandinG2 (PGG2) and PGH2 and subsequently to a variety of eicosanoids. COX-2 is one of the isoforms of COX, which was upheld mainly as an inflammatory, inducible enzyme, having role different than that of COX-1. However, more recent studies are beginning to reveal additional functions of COX-2, especially in oral lesions.Most commonly studied area of interest being oral squamous cell carcinoma, along with salivary gland tumors, reactive inflammatory lesions and so on. The objective of this review is to discuss the role of COX-2 in various oral lesions.