The literature relating to tobacco smoking has been reviewed and is discussed under a number of headings. The smoking habits of Australians and people of other countries, the constituents of tobacco smoke and the different types of tobacco are discussed. The effects of tobacco smoke on lung defences and and function are outlined and the evidence relating cigarette smoking to lung cancer in Australia, the UK and the USA is reviewed. The relationship between cigarette smoking and diseases which chronic air flow obstruction is outlined. Differences in smoking-related diseases in males and females and the effects of stopping smoking are included in the discussion.