Oral submucous fibrosis is a chronic, complex, premalignant lesion of the oral cavity, characterized by juxta-epithelial inflammatory reaction and progressive fibrosis of the submucosal tissues (the lamina propria and deeper connective tissues). As the disease progresses, the jaws become rigid to the point that the person is unable to open the mouth.The condition is remotely linked to oral cancers and is associated with areca nut or betel quid chewing, a habit similar to tobacco chewing, is practiced predominantly in Southeast Asia and India, dating back thousands of years.This is a highly potent and chronic pre-cancerous condition that affects various portions of the oral cavity as well as the pharynx.This review is done to create awareness about oral submucous fibrosis.