Acute myocardial infarction (AMI) is a subset of the acute coronary syndromes and can be classified as being either a ST-segment elevation myocardial infarction (STEMI) or a non-ST-elevation myocardial infarction (NSTEMI). A clear distinction between STEMI and NSTEMI is essential because of the differences in management. The purpose of this review was to first discuss the epidemiology, pathophysiology, and diagnosis of AMI. The risk stratification and therapy of patients with STEMI and NSTEMI will then be reviewed as well as the complications of AMI.