UP TO THIS writing, 44 cases of nontuberculous infections of the respiratory tract in which the patient was treated with streptomycin have been fully studied in Army hospitals. The number of cases is small because relatively few pleuropulmonary infections are caused by organisms which do not respond satisfactorily to the sulfonamide compounds and penicillin. The sulfonamide compounds have a pronounced effect on bacterial pulmonary infections caused by Diplococcus pneumoniae (Pneumococcus) except type III and the hemolytic streptococci. Hemophilus influenzae, Klebsiella pneumoniae and Staphylococcus aureus infections are less strikingly influenced. One of the chief advantages of the sulfonamide compounds is that they are effective when administered orally. The common types of pulmonary infection which respond favorably to the sulfonamide compounds improve even more dramatically when penicillin is administered. The repeated and wearying injections necessary when this antibiotic is used are more than compensated for by the greater efficacy and relative freedom