Acute myocardial infarction (AMI) causes significant mortality and morbidity. Timely diagnosis allows clinicians to risk stratify their patients and select appropriate treatment. Biomarkers have been used to diagnose or rule out AMI. An increasing number of novel biomarkers have been identified to predict the outcome following AMI or acute coronary syndrome (ACS). This may facilitate tailoring of appropriate therapy to high-risk patients. This review focuses on a variety of promising biomarkers which provide diagnostic and prognostic information.