Cigarette smoking is firmly established as a risk factor for coronary heart disease, stroke and peripheral vascular disease, and is associated with increased cardiovascular mortality. A possible explanation for this relation is that smoking increases the development of atherosclerosis. Indeed, tobacco smoking has been associated with modified lipids levels, decreased fibrinolysis, increased fibrinogen levels and changes in endothelial and platelet functions for instance, which are themselves either known risk factors for or early features of atherosclerosis. Passive smoking, defined as the the involuntary exposure of non-smokers to tobacco combustion products in the indoor environment is now convincingly linked to heart disease mortality and morbidity. Stopping smoking works, decreasing cardiovascular mortality and morbidity within 5 years, whatever the age and sex of the previous smoker.