Recently there has been an increase in the incidence of polyneoplasias (PNP) of various organs. This is associated with certain advances in the treatment of malignancies with prolonged survival on the one hand and with better diagnosis and the emergence of new instrumental studies. The diagnosis and treatment of lung cancer as a component of PNP) currently remains a great challenge. In 1985 to 2004, the Acad. B. V. Petrovsky Russian Research Center of Surgery, Russian Academy of Medical Sciences, and Moscow Cancer Dispensary One treated 403 patients for lung cancer detected in combination with an extrapulmonary malignant tumor or second lung cancer, which amounted to 8.9% of the patients operated on for lung cancer. Primary malignancy of the lung and secondary neoplasm were synchronously and metachronously diagnosed in 165 (40.9%) and 238 (59.1%) patients, respectively. Lobectomy was performed in 207 (51.4%) patients while 79 (19.6%) patients underwent sublobar resection. Three- and 5-year overall survival was 43.4 and 30.6%, respectively. After radical operations, better 5-year survival rates were observed in patients with metachronous lung cancer in PNP (32.5% than in those with synchronously detected one (27.9%) (p