Analysis of 257 patients with tuberculosis of respiratory organs and 292 patients with other diseases of the organs of thoracic cavity, in whom the previously carried out clinical and roentgenological examinations had failed to exclude the presence of specific process, is presented in this article. The authors discuss the indications for carrying out computerized tomography of the organs of thoracic cavity and specify their application with respect to different forms of tuberculosis. They also present a short description of the method of computerized tomography. The authors concentrate mainly on the analysis of CT's diagnostic power and, particularly, on the differential diagnosis of tuberculosis of respiratory organs. They also discuss the limitations of this method and compare them with the same of traditional roentgenologic examinations, bronchoscopy and other diagnostic methods.