Abstract 1. 1. Tuberculosis of the mouth should be considered as a possible diagnosis in cases of chronic ulceration of the mouth. 2. 2. While always secondary to pulmonary tuberculosis, the lung lesion may give few, or no, symptoms. It is in this group of cases in which errors in diagnosis are most likely to occur. 3. 3. Radiation therapy may be of some value in the treatment of these cases.