Oral submucous fibrosis is an oral precancerous condition characterized by inflammation and progressive fibrosis of the submucosal tissues resulting in marked rigidity and inability to open mouth. Oral submucous Fibrosis have variable etiologies but it is mainly associated with the practice of chewing betel quid containing areca nut, a habit common in Indian sub-continent. Hence the disease is prevalant in Indian population. OSMF still remains a dilemma to the clinicians. Due to significant morbidity and mortality associated with this disease, it needs urgent attention.The current textbook comprehensively deals with background,etiopathogenesis, clinical symptoms,histopathology and management of Oral Submucous Fibrosis.