Lung cancer is 4.5—7 times more frequent among the people sick with tuberculosis in contrast to the main population. A clinical morphological examination was performed for the specimen from 344 patients with a peripheral lung cancer and from 70 patients suffering from focal pulmonary tuberculosis. The examination confirmed the tuberculosis significance as a background disease for a lung cancer development. Fibrosis foci of tuberculosis origin have been determined on tumors in 73 percent of the “cancer in cicatrix” cases, in post-tuberculosis foci the specific weight of hard degrading collagens IV,V and collagen of the type III grew. The latter collagen can be found in an embryonal lung. The importance of tuberculosis for the lung cancer development is confirmed by a relatively frequent detection of precancerous changes in the iung epithelium for the patients suffering from the post primary pulmonary tuberculosis (23 percent). There was obtained new data on the production of the insuiin type growth factor 2 and protein of types 2 and 4 by the tuberculosis granuloma’s cells. These parameters were derived with the use of the ¡mmunohistochemical method. The described growth factor is a strong mitogen able to paracryinically stimulate the lung epithelium proliferation. In its turn this provokes a lung pre-cancer and cancer development. A correlation between the tuberculosis and the lung cancer due to chronic inflammation decompensation, reparative regeneration and sclerosis is discussed. The expediency of a surgical treatment for the patients with chronic focal tuberculosis is considered.