Tuberculosis of the mandible, although heretofore considered to be rare, has been observed not infrequently. Of the fourteen cases reported in this paper, eight were seen within a period of two and one-half years. The majority of the patients belonged to the second and third decades of life. Swelling, discharging sinuses, and, occasionally, trismus of the jaw were the chief complaints. About 43 per cent. of the patients in this series had tuberculous lesions in other bones of the body, and tuberculosis of the skull was coexistent in 29 per cent. In ten of the cases in which the chest was studied roentgenographically, evidence of tuberculosis either in the lungs (eight cases) or in the pleura (two cases) was seen in 100 per cent. Pathogenically, it appears that the tuberculous infection of the mandible is almost always hematogenous, originating from a primary focus elsewhere in the body, most likely in the lungs, although the mandible may be involved from extension of a tuberculous lesion of the mucous membrane of the oral cavity or from infected gingivae about carious teeth. Rational therapy must emphasize general antituberculous measures in addition to local treatment of the tuberculous lesion of the mandible.