The American College of Cardiology/American Heart Association and the European Society of Cardiology each recently published updated guidelines for management of patients with acute ST elevation myocardial infarction. In this article, we highlight the most important new recommendations, review their supporting data, and describe differences between the guidelines.Key aspects of these updates include detailed guidance regarding the selection of a reperfusion strategy and the incorporation of newer adjunctive antithrombotic agents. Both new guidelines suggest caution in the administration of intravenous β-blockers, avoidance of nonsteroidal anti-inflammatory agents, and support a more aggressive approach to secondary risk factor management.The 2 guidelines have some nuanced differences as well as some recommendations that are unique to each guideline. They present different levels of support for the 4 available adjunctive parenteral anticoagulants, vary in their endorsement of routine elective coronary angiography after fibrinolysis, and cite different targets for low density lipoprotein long-term. Major unique recommendations include the American College of Cardiology/American Heart Assocaition's emphasis of a stepped approach to analgesia in patients with musculoskeletal pain beginning with acetaminophen or aspirin and a lower target international normalized ratio in patients receiving warfarin, aspirin, and clopidogrel. Meanwhile, unique recommendations in the European Society of Cardiology guidelines include measures to prevent/treat microvascular obstruction and reperfusion injury associated with percutaneous coronary intervention and greater emphasis on maintaining eugylcemia.As these guidelines represent an evidence based approach, health care providers should become familiar with the new data and the resultant updated recommendations to ensure optimal treatment of their patients with ST-elevation myocardial infarction.