One of the most common complaints encountered in the emergency department is chest pain. In many evaluations, the leading diagnostic consideration is an acute coronary syndrome (ACS). ACS refers to a spectrum of coronary artery pathologies, including unstable angina, non-ST segment elevation myocardial infarction, and ST-segment elevation myocardial infarction. The distinction between subtypes of ACS guides acute diagnostic and management decisions. Failure to diagnose and manage ACS properly is a frequent cause of medico-legal litigation. In this article, we review the initial identification and critical management steps in patients presenting to the emergency department with ACS.