Acute coronary syndromes include ST-elevation and non-ST elevation myocardial infarction, and unstable angina pectoris. These are characterised by the acute onset of chest pain. For the diagnostic work up in the acute phase, ECG and the assessment of cardiac markers play a central role. For patients with ST-elevation, primary interventional therapy is the first choice. For patients with an acute coronary syndrome without ST-elevation, a risk adapted therapeutic strategy should be chosen. High risk patients (elevated troponins, clinical, rhythmological and hemodynamic instability, ST-depression and diabetes mellitus) should be treated by an early invasive approach with angiography performed within 48-72 h. Low risk patients should be treated conservatively. For all patients who are treated interventionally, the administration of an aggressive antiaggregatory therapy including aspirin, clopidogrel, glycoprotein IIb/IIIa inhibitors and heparin is indicated in the acute phase. In the chronic phase, the treatment of cardiovascular risk factors is of paramount importance.