An understanding of the behavior of oral malignancy is necessary to insure early detection of this disease by the dentist. Alterations in oral mucosa such as keratotic plaque, erythematous granular erosions, and foci of pigmentation'often demonstrate a microscopic spectrum of epithelial atypia. Of primary concern to the dentist is the fact that carcinoma may mimic periodontal disease and often occurs in inaccessible areas of the mouth such as the base of the tongue. Metastasis occurs more often in lesions over 2 cm in size and studies suggest that a large percentage of patients have positive nodes at the time of initial examination. The dentist's approach to oral malignancy must include adequate examination, proper use of biopsy and cytology techniques, and expeditious referral.