Leukoplakia as a medical term has been encumbered by a hodgepodge of synonyms and interpretations. It also has been a term associated with strong emotions with respect to an implied malignant potential. It now is regarded as potentially malignant, with varying degrees of risk for transformation. Leukoplakia at its major anatomic site of occurrence, the oral cavity, recently has been redefined, classified, and staged as a preamble to a more rational approach to the clinicopathologic study of leukoplakia. These changes are presented, as are current assessments of proliferative verrucous leukoplakia, verrucous hyperplasia, palatal white lesions, effects of smokeless tobacco on the oral mucosa, hairy leukoplakia, and lichen planus.