BACKGROUND Oral submucous fibrosis (OSF) is an insidious precancerous disease affecting the oral cavity, pharynx and upper digestive tract. Its etiology is linked directly to betel nut use, which is common to the Indian subcontinent. With the increase in immigration of people from the Indian subcontinent to the United States, many American dental professionals will encounter this disease in the near future. The author provides a general overview of OSF. METHODS The author provides a literature review of OSF, including its epidemiology, etiology, clinical presentation, histopathology and treatment modalities. RESULTS OSF is a precancerous oral disease linked definitively to the use of betel nut. It is endemic to people in the Indian subcontinent. Patients' primary complaint is progressive trismus. Treatment is based on disease severity. CONCLUSIONS OSF is a debilitating but preventable oral disease. Its incidence in the United States will increase as the South Asian immigrant population expands. Consequently, American dental professionals may encounter patients with this disease, and it is important that they are aware of it. In addition, for dental care professionals practicing in a South Asian American community, public health education is important to inform the population about the deleterious oral health effects of betel nut consumption.