Material presented in this paper has been gathered from the author's experience with 200 patients who were afflicted with diabetes mellitus and complicating pulmonary tuberculosis. Concepts are reviewed which deal with the cause of increased susceptibility to tuberculosis of patients suffering from diabetes mellitus. Some peculiarities of the clinical substrate of pulmonary tuberculosis in these individuals are discussed. Therapeutic precepts applied in the treatment of the two diseases are outlined. In well controlled diabetes, adequate antimicrobials and adjunct measures are bound to bring about a recovery rate from pulmonary tuberculosis which compares favorably with that of tuberculous patients without diabetes. I have found that after proper institutional treatment, diabetics with pulmonary tuberculosis may become eligible for outpatient care, provided facilities and personnel are available for competent medical supervision. Under such circumstances, their chances for complete socio-economic rehabilitation are favorable.