ORAL SUBMUCOUS FIBROSIS(OSMF) is a debilitating but preventable oral disease. It was first described by Schwartz in 1952 among five Indian females from Kenya and he designed the term 'Atropica Idiopathica Mucosae Oris to this condition. In 1953, Joshi described this condition as 'Submucous Fibrosis'.A condition resembling OSMF was described as early as 600 BC and it was named as 'VIDARI' having features of progressive narrowing of mouth, depigmentation of oral mucosa and pain on taking food.A more serious complication of this disease is the risk of the development of oral squamous cell carcinoma.This book emphasis on the preventive aspect of conversion into malignancy.