The oral cavity is one of the predominant and prevalent sites of development of potential malignancies, since it comes into direct contact with many carcinogens. Despite monitoring the original tumour site following an advanced surgical and non-surgical therapy, the overall mortality rate remains unchanged probably due to the recurrence of the tumour either locally or at a remote site. Field Cancerization also called field defect or field effect is a well-known process of transformation of an existing precancerous lesion into a malignancy. This definition is often used to describe the development of abnormal tissues around a tumorigenic area, resulting into an oral multifocal cancer in individual sites, which later coalesce and create atypical areas, even after complete surgical removal of the tumour. Early detection and monitoring of the field may have profound implications for Cancer Prevention.