Patients hospitalized in Kentucky (USA) TB sanatoriums were interviewed to determine the degree of understanding of their disease and its implications in preparation for ambulant care. Eighty percent knew their diagnosis and 56 percent recognized TB as contagious. Although two-thirds could give at least a visual description of their medication, at least 50 percent demonstrated a deficiency in knowledge that was needed to be corrected before adequate compliance away from the hospital environment could be expected. Further, only 25% knew the criteria for discharge. Among the several patient factors analyzed to explain the difference in knowledge levels, only age was consistently significant. Positive effort was recommended to educate the patient for adequate ambulant or home treatment.