While the lung cancer is detected, the majority of the patients could not be surgical cured. Thus appears the great necessity of prevention, of a more efficient treatment and the developing of new methods for early detection. The first screening trials for lung cancer had negative results. None of the studies had no prove in decreasing of mortality by screening for lung cancer. The lack of sensitivity of thoracic radiographs and sputum cytology was leading the investigators to use the monoclonal antibodies in detecting the neoplastic changes in sputum, the spiral computerized tomography with low dose of radiations, the autofluorescence bronchoscopy and more recent the positron emission tomography, offering the possibility of reducing mortality by early detection in lung cancer.