Cigarettes appearance in the middle of 19th century turns tobacco into a general consumption product with ill-fated consequences. Technological process and the means by which tobacco dependence appears were hidden from medical world for a long time by the tobacco companies. Cigarette smoke represents a mixture of 4000 toxic substances including carcinogens, organic compounds, solvents, gas substances (CO). We can add another 600 additives which are used in the technological process. Tobacco dependence is defined by the daily cigarette consumption, difficult quitting and probability for withdraw symptoms. Among the smoke effects on respiratory system, we can identify two main mechanisms: inducing inflammation and mutagen if - carcinogenic effect. Inflammation consists of ciliary toxicity, increased mucus secretion and accumulation of activated inflammatory cells in the respiratory tract. The risk for lung cancer is directly related to the presence of CYPlA1 alleles and reduced glutathione S-reductase activity.