The acute coronary syndromes (ACS) remain a diagnostic and prognostic challenge for today's physician. Over the past decade, studies have identified several serologic biomarkers to aid the clinician in assessing risk and predicting outcomes in ACS. Still others are being identified that show promise for increasing the accuracy with which this risk is assessed. However, further research remains necessary to identify the perfect cardiac biomarker or combination of markers and to define their roles in clinical management of ACS patients.