Premalignant disorders of the oral mucosa primarily includes oral leukoplakia. The critical problem is to predict future malignant development. Several markers of malignant development have been suggested, however, possibly the most important is a non-homogeneous clinical appearance. There is no evidence that surgical intervention reduces the risk of malignant transformation. Oral cancer is relatively rare, however, easily detectable and preventable; tobacco and alcohol are by far the most important aetiologic factors. Increasing trends in rates of intraoral cancer are seen in many countries.