As the leading cause of cancer related death world wide, lung cancer is responsible for an enormous amount of suffering and disability. Detection of disease when it is surgically curable is associated with far greater odds of cure, and therefore it is a disease for which mass screening of high-risk populations has significant potential benefit. Starting in 2011, with the publication of the National Lung Screening Trial from United States (U.S.), mass screening programs have emerged throughout the U.S., as well as in other countries. More recently, large European screening trials have confirmed the potential mortality benefit of lung cancer screening. This invited non-systematic review paper covers the trial that data justify mass-screening, for lung cancer and proposes strategies for maximizing benefits and minimizing harms in the context of a mass public health lung cancer screening program.