Given the importance of fibrous tissue in leading to myocardial dysfunction, non-invasive assessment of fibrosis could prove a clinically useful tool in heart failure (HF) patients. Biomarkers may be used for early detection of otherwise subclinical disease, diagnostic assessment of an acute or chronic clinical syndrome, risk stratification of patients with a suspected or confirmed diagnosis, selection of an appropriate therapeutic intervention and monitoring the response to therapy. Extracellular matrix (ECM) biomarkers in HF are promising biomarkers. They are able to detect early changes in heart and large vessel structure and function and transition to HF. High ECM biomarker levels have been associated with poor outcome. The ability of treatment to reduce myocardial fibrosis in HF patients may be monitored by the measurement of various serum peptides arising from the metabolism of collagen types. Biomarkers may be selectively influenced by pharmacological agents.