Squamous cell carcinoma (SCC) is the most common form of oral malignancy and is often preceded by premalignant lesions, some of which are more likely to progress to carcinoma than others. In this study, a panel of monoclonal antibodies (AE1/AE3, cytokeratin [CK] 14, Ki-67 and p53) is applied to 10 cases of human oral tissue in each of six categories to establish staining patterns indicative of which lesions are more likely to progress to malignancy. The six tissue categories are normal tissue; abnormal benign lesions; mild, moderate and severe dysplasia; and SCC. A statistical analysis of Ki-67 and p53 immunoexpression is performed. The results showed that AE1/AE3 and CK 14 expression was reduced as a late event in oral carcinogenesis, particularly in poorly differentiated SCC. Expression of Ki-67 and p53 proved to be a weak but statistically significant predictor of malignant progression in oral tissue.