Oral submucous fibrosis (OSMF) is a peculiar disease that has recieved considerable attention in the past and continues to pose a challenge especially from a management perspective because of its chronic debilitating and resistant nature. The potential for malignant transformation in submucous fibrosis is considered high. It still remains enigmatic and characterization of its pathogenesis is met with difficulties primarily, due to the inability to prove a cause-effect relationship in ascribing any known agent in its causation. Though habit of areca nut chewing has been strongy linked to this condition majority of investigators now up uphold the multifactorial origin of this disorder with probable genetic predisposition in its causation. This handbook gives complete review on the possible etiopathogenesis, clinical & histopathological features along with various treatment modalities of OSMF. It will help dental students and practitioner to get better understanding of this premalignant condition.