Oral submucous fibrosis (OSMF) is an oral precancerous condition characterized by inflammation and progressive fibrosis of the submucosal tissues resulting in marked rigidity and trismus. OSMF still remains a dilemma to the clinicians due to elusive pathogenesis and less well-defined classification systems. Over the years, many classification systems have been documented in medical literature based on clinical, histopathological, or functional aspects. However, none of these classifications have achieved universal acceptance. Each classification has its own merits and demerits. An attempt is made to provide and update the knowledge of classification system of OSMF so that it can assist the clinicians, beneficial in researches and academics in categorizing this potentially malignant disease for early detection, prompt management, and reducing the mortality. Along with this, pathogenesis and management have also been discussed.