Demand for donor hearts exceeds supply, and a significant number of patients die while awaiting transplantation. Within the pool of currently unused potential donor hearts, a proportion may be suitable for transplantation but are declined due to anticipated poor function. Despite current assessment methods, in some donor hearts accepted for transplantation early graft failure develops in the recipient. Current methods of assessment are inadequate, and there is a potential for biomarkers to improve identification of satisfactory hearts for transplantation or hearts destined to fail in the recipient. Biomarkers are routinely used to diagnose and risk-stratify myocardial infarction, acute coronary syndromes, and heart failure. Some of these might facilitate donor heart assessment. Cardiac troponins, cytokines, inflammatory markers, natriuretic peptides, and intracellular proteins may each have discriminant value. This review details the current status of biomarkers in the assessment of donor hearts.