In the last 20 years there have been enormous advances in our understanding of the acute coronary syndromes and how to manage patients presenting with them. In the 1980s, we began to understand the importance of thrombus formation was in the pathophysiology of acute coronary syndromes. Randomized studies also showed that appropriate antithrombotic therapy reduced the subsequent occurrence of myocardial infarction and death. In the 1990s, other therapeutic modalities and particularly percutaneous coronary intervention have come to the forefront as effective therapy in these syndromes. The glycoprotein IIb/IIIa receptor antagonists along with coronary stent implantation have proved extremely beneficial in short- and long-term management. We also have learned the importance of risk-factor modification in preventing subsequent events. In the future, greater efforts will focus on primary prevention.