Introduction: Oral submucous fibrosis (OSF) is an insidious chronic disease affecting the mucosa of any part of the oral cavity and occasionally extending into the pharynx and esophagus. It occurs at any age but is most commonly seen in young adults between 25 and 35 years (2nd–4th decade). Characteristic male preponderance is reported in the literature with strong association with the chewing of smokeless tobacco. Aims: To find a provisional diagnosis of oral submucous fibrosis. Case Report: The present case report describes a case of OSF in a 40-year-old male patient. Discussion: The frequency and duration of chewing also contribute to the stage of fibrosis. Arecoline in areca nuts is the main causative agent. OSF is a potentially malignant disorder with a 7%–13% malignant transformation rate. Conclusion: The treatment of OSF depends on the degree of involvement and timely diagnosis. Patients with OSF need treatment for trismus correction, reconstructive surgery for any simultaneous oral malignancy