Although the number of smokers per capita has declined appreciably in the United States in the past 30 years, smokers still make up about one quarter of the adult population. It does not appear that the number of US smokers will decrease further in the next century, and the number may even increase due to the popularity of smoking among teenagers. Epidemiological data indicate that women are more susceptible, dose-for-dose, to the adverse effects of tobacco smoke. Since women make up a large percentage of today s smokers, lung cancer rates may increase in the future. Current guidelines recommend against lung cancer screening based on chest x-ray and sputum morphology; however, new highly sensitive detection methods are available that may make screening more effective, especially if combined with analysis of risk factors for lung cancer and biomarkers of damage to the airways that may identify individuals at highest risk for lung malignancies. Lung cancer will continue to be a major public health problem in the next century. Advances in the field of early detection may make lung cancer screening practical and effective in the near future.