ST2 and galectin-3 are emerging biomarkers in the field of heart failure and have been extensively studied, and that whether they provide additional prognostic value on top of the clinical models and the gold standard in HF, (NT-pro)BNP. Our aim was to provide a comprehensive review of these emerging HF-related biomarkers in chronic, acute and incident heart failure. Regardless of the type of heart failure, both biomarkers seem to have an additional effect on top of the clinical model including natriuretic peptides. Strategies that combine multiple biomarkers may ultimately prove to be beneficial in the guidance of HF therapy in the future. However, additional prognostic value appears to be limited, and what we need is to prospectively test the consistent observations, which then might lead to the implementation of ST2 and galectin-3 in heart failure algorithms.