Percutaneous transluminal coronary angioplasty is now largely applied either to stable or unstable patients suffering from angina pectoris. The procedural success rate and the incidence of acute complications are now comparable in the 2 population of patients. Very recent data have also shown that there is no difference in restenosis between patients with stable or unstable angina. Therefore, by now, in such unstable coronary syndromes the choice of surgical therapy is mainly determined by the presence of multivessel disease or by depressed left ventricular function. However, the possibility to obtain a complete revascularization by angioplasty or to stabilize the patients treating only the "culprit" vessel, may increase the number of unstable patients shifting from surgery to angioplasty.