The ability to measure the appearance of cardiac specific forms of troponin in the blood represents a major advance in the clinical assessment of patients with many types of cardiovascular disease, especially acute coronary syndromes. In this review we focus on the utility of troponin in heart failure where this biomarker has emerged as an independent predictor of prognosis providing information beyond clinical assessment and measurement of b-type natriuretic peptides. The novel clinical role of troponin in a variety of states associated with myocardial injury, including chemotherapy and patients with cardiovascular risk factors, is discussed.