The dominant role of tobacco smoking in the causation of lung cancer has been repeatedly demonstrated over the past 50 years. Current lung cancer rates reflect cigarette smoking habits of men and women in the past decades, but not necessarily current smoking patterns, since there is an interval of several decades between the change in smoking habits in a population and its consequences on lung cancer rates. Over 90% of lung cancer may be avoidable simply through avoidance of cigarette smoking. There is at present a huge premature loss of life world-wide caused by smoking. Rates of lung cancer present in central and eastern Europe at the present time are higher than those ever before recorded elsewhere; lung cancer has increased 10-fold in men and eightfold in women in Japan since 1950. There is a world-wide epidemic of smoking among young women which will be translated into increasing rates of tobacco-related disease, including cancer, in the coming decades. There is another epidemic of lung cancer and tobacco-related deaths building up in China as the cohorts of men in whom tobacco smoking became popular reach ages where cancer is an important hazard. Many solutions have been attempted to reduce cigarette smoking and increasingly many countries are enacting legislation to curb this habit. Cigarette smoking remains the number one target for Public Health action aimed at reducing cancer risk in the general population. General practitioners, hospital physicians and everyone working in oncology have a particularly important exemplary role to play in this process.