This paper reviews the current contribution of the biochemical marker determination to clinical cardiology and discusses some important developments in this field. Biochemical markers play a pivotal role in the diagnosis and management of patients with acute coronary syndrome (ACS), as witnessed by the incorporation of cardiac troponins into new international guidelines for patients with ACS and in the re-definition of myocardial infarction. Despite the success of cardiac troponins, there is still a need for the development of early markers that can reliably rule out ACS from the emergency room at presentation and also detect myocardial ischaemia in the absence of irreversible myocyte injury. Under investigation are two classes of indicators: markers of early injury/ischaemia and markers of inflammation and coronary plaque instability and disruption. Finally, with the characterisation of the cardiac natriuretic peptides, Laboratory Medicine is also assuming a role in the assessment of cardiac function.