Lung resection specimens of 677 surgical patients were studied to determine the clinical meaning of the absence of Mycobacterium tuberculosis (MTB) in sputums of pulmonary tuberculosis patients, who show none of the clinical manifestations of tuberculosis, except the alterations seen on x-ray pictures. There were 2 patient groups: group 1 comprised. 409 patients referred to a sputum-positive out-patient follow-up group, group 2 included 268 patients referred to a sputum-negative out-patient follow-up group, who showed the presence of mycobacteria in their lung resection specimens by luminescence microscopy in 147 (54,8 %) cases, and of them. 58 (39,4 %) cases showed, high counts of mycobacteria. By culture method. MTB were identified in 35 (13,0 %) patients, and. in 14 (40,0 %) cases growth was either medium or massive. The question was studied of how should one treat this fact: carrier state or latent tuberculosis? We conclude that patients with the absence of bacterial expectoration confirmation by laboratory methods and. the absence of disease manifestations, but who have definite morphologic signs of tuberculous alterations in the lungs, should be treated like epidemiologically risky group and. should be appointed to radical surgical treatment methods.