Lung cancer is the most frequent cause of death from cancer in men. In addition its prevalence among women is currently rapidly increasing. Main risk factors are smoking, exposure to asbestos and genetic factors. Current screening methods do not allow early detection and, hence, lung cancer is usually diagnosed at an advanced stage. The stage of the disease affects survival. In non-small cell lung cancer the probability of 5-year survival for patients is about 43% with stage I, 23% with stage II, 17% with stage IIIA and 2% with stage IIIB disease. Surgery plays a major role in patients with non-small cell lung cancer in stages I, II and maybe IIIA. In small cell lung cancer the probability of 5-year survival is about 10% for patients with limited disease and less than 1% for patients with extended disease. Although surgery plays a role in stage I to stage IIIA, chemotherapy remains the most important mode of therapy in small cell lung cancer. In stages I to IIIA, however, combined treatment modalities might improve outcome of the patients with small cell lung cancer.