Worldwide, lung cancer is the most common cancer in terms of both incidence and mortality with 1,04 million new cases per year and 921,000 deaths, with the highest rates currently observed in Europe and North America. Once diagnosed, the 5-year survival rate for lung cancer in Europe fluctuates between 8% and 12%. Smoking is found in 90% of lung cancer cases. A successful, straightforward preventive strategy to reduce the incidence of the disease is a sustained prevention of tobacco consumption. However, because of the persistent risk among former smokers, early treatment following early diagnosis is still considered as potential development. There is currently no recommended screening strategy for lung cancer, reflecting the negative results of trials showing no mortality reduction following screening programs using chest X-ray and sputum examination. Low dose computed tomography has been recently assessed as a screening tool in observational studies suggesting better impact than the one obtained with chest X-ray. Five RCTs are currently under way to evaluate low dose computed tomography as a screening tool for lung cancer, with a total of 133,000 subjects. First results are expected for 2007. Until the completion of these studies, wild screening intervention should be avoided.