Smokers differ from nonsmokers in the way they present with acute coronary syndromes and in how they respond to treatment. Although smoking increases the risk of a coronary event and accelerates the progression of established atherosclerosis, paradoxically, smokers have better short-term survival after an acute myocardial infarction, mainly because they are younger and have more favorable coronary anatomy. Thrombolysis appears to be a better treatment in smokers than in nonsmokers, probably because thrombosis plays a more important role in the pathogenesis of acute coronary events in smokers. Patients who continue to smoke after angioplasty or bypass surgery have a worse outcome than nonsmokers or quitters. The 2.5- to 3-fold increase in risk for myocardial infarction or stroke in smokers compared with nonsmokers decreases exponentially after smoking cessation. By 4 years the risk is only slightly higher than the risk of a subject who never smoked.