The pathogenetic relationship between pulmonary tuberculosis and lung cancer in their concurrence is now still the subject of discussion. Objective. To study the pathogenetic relationship between pulmonary tuberculosis and lung cancer. Material and methods. The investigators examined surgical material from 51 patients (41 men) aged 41—73 years (mean age, 63.7 years) with pulmonary tuberculosis concurrent with lung cancer. They also studied tumors, tuberculous caverns, infiltrates, and foci with surrounding macroscopically intact lung tissue, as well as fibrotic changes by histological, histochemical and immunohistochemical examinations. Results. Previous tuberculosis can be considered as a risk factor for lung cancer. Central cancer was more common in patients with inactive, chronic tuberculosis with a predominance of fibrotic processes in the root of the lung and in its hilar zones. Fibrous-cavernous tuberculosis and cavernous tuberculosis were more frequently concurrent with central cancer; peripheral tumors mainly occurred in infiltrative tuberculosis and tuberculomas. Conclusion. The findings suggest that in a number of cases, cancer and tuberculosis may be anatomically close, developing in the same anatomical unit — the lung. However, this does not indicate an unambiguous etiopathogenetic relationship between pulmonary tuberculosis and lung cancer. The relationships between pulmonary tuberculosis and lung cancer are much more complex and do not fit into the simple scheme of cause-and-effect relations.