Clinical trials have shown that the towering of total cholesterol or low-density lipoprotein cholesterol levels substantially reduces the risk of morbidity and mortality due to coronary heart disease. However, the benefits of lipid lowering in patients with acute coronary syndromes have been less well studied. The majority of statin trials excluded patients who had experienced recent unstable angina or acute myocardial infarction and, therefore, were not able to evaluate the potential beneficial effects that may result from early statin therapy. However, new evidence is emerging that statins may be effective immediately after an acute coronary event. Recent observational studies indicate that patients who are treated with a statin early after a coronary event have a more favourable outcome than those who are not, and retrospective analyses of clinical trial databases of patients with acute coronary syndromes have also shown this pattern. Statin therapy favourably impacts interrelated pathophysiologic mechanisms that are intimately involved in the pathogenesis of acute coronary syndromes, most notably endothelial function, platelet thrombus deposition and inflammation. The first clinical trial to study early statin intervention in acute coronary syndromes is the Myocardial Ischemia Reduction with Aggressive Cholesterol Lowering (MIRACL) study, which has demonstrated that lipid-lowering therapy initiated during hospitalization results in an early reduction in the incidence of recurrent ischaemic events. (C) 2004 Published by Elsevier Ltd on behalf of The European Society of Cardiology.