The immediate and long-term results of surgical treatment for cancer of the middle lobe of the lung in 84 patients are discussed. Radical procedure was used in 65 (77.4%) patients. Postoperative lethality was 6.1% (4 cases out of 65). 30.2% survived over 5 years. Regional lymphatic node involvement was found to significantly affect the end results. At zero involvement, 5-years survival was 38.7% whereas at involvement 1-2, it dropped to 8.3%. With regional nodes intact, midlobectomy was survived for more than 5 years by 20.0%, bilobectomy--71.4%, and pneumonectomy--35.7%. Maximal advantage is assured by bilobectomy since it allows for adequate lymphadendissection, midlobectomy being not radical enough for surgical treatment of lung cancer.