The present invention provides methods for diagnosis and prognosis of lung cancer using expression analysis of one or more groups of genes, and a combination of expression analysis with bronchoscopy. The methods of the invention provide far superior detection accuracy for lung cancer when compared to any other currently available method for lung cancer diagnostic or prognosis. The invention also provides methods of diagnosis and prognosis of other lung diseases, particularly in individuals who are exposed to air pollutants, such as cigarette or cigar smoke, smog, asbestos and the like air contaminants or pollutants.