Verruca vulgaris is an uncommon oral lesion which is caused by an infectious agent, HPV. These growths have many clinical features in common with other oral lesions, the most serious of which are verrucous carcinoma and verrucoid squamous cell carcinoma. These various lesions can usually be separated on the basis of clinical and microscopic features. In some cases, however, immunohistochemical studies and DNA hybridization studies may be necessary before an exact diagnosis can be made.