While much has been written on leukoplakia buccalis, there is still some difference of opinion regarding certain of its features. The subject was discussed before this section in 1922 by Hazen and Eichenlaub,1and since then has been reviewed by Maderna2in Italy and by DeForest3in this country. My object in again introducing the subject is to give the results of personal experience, especially in their relation to its etiology. The relationship of syphilis as a precursor of the disease and of cancer as a possible complication are perhaps the most important points to consider. Although leukoplakia affects other mucous membranes besides those of the oral cavity, the latter alone will be considered in this communication. SYMPTOMS Leukoplakia varies greatly in appearance according to its age and development. In the early stages, the process is superficial and, as a rule, the patient is not aware of