SummaryA series of 53 adult patients whose treatment had been started one year (or more) previously have been studied. In this group of patients 68 % were still alive after 3 months, 49 % after 6 months, 43 % after 9 months and 35 % after one year.The authors examined whether certain symptoms observed at the time of admission or 30 days after beginning the treatment could be of any pronostie value to determine the chances of recovery with streptomycin therapy.At the beginning of the treatment :One must consider as being :a)fatal : neurologic symptoms indicating focal brain lesions ;b)of poor prognosis :1°fibro-caseous pulmonary tuberculosis;2°marked modifications of spinal fluid (index 7 or above) ;c)of good prognosis :1°no lesions of the lungs detectable by×ray examination ;2°pulmonary miliary tuberculosis;3°miliary tubercules in fundus oculi ;4°no marked modification of spinal fluid.After 30 days of treatment :Persisting fever and psychic disorders are of poor prognosis; the onset of neurological symptoms of brain lesions during this period of treatment is of very bad outlook.The prognosis is also related with the ways of administration of streptomycine. The best results were obtained by ininterrupted treatment during 6 months.