Endothelial dysfunctions, nonocclusive coronary thrombi and plaque ruptures cause unstable angina pectoris, an instability of coronary artery disease and are accompanied by an increased risk of sudden death and acute myocardial infarction. Clinical factors, angiography and newer laboratory measurements help to identify patients who should be assigned to surgical or interventional revascularization or to medical therapy. In contrast to revascularization procedures, medical therapy is available everywhere at any time. Monotherapy either by use of betablockers or calcium antagonists can not be recommended while nitrates are a cornerstone in medical therapy for unstable angina. Nitrates in combinations with betablockers and calcium antagonists have been shown to reduce the number and duration of ischaemic episodes. These combinations also reduce the incidence of acute myocardial infarction, sudden death and the need for surgical revascularization.