Heart failure (HF) is a major problem for our contemporary societies in terms of prevalence, mortality and cost. Natriuretic peptides are recognized biomarkers for the diagnosis of HF but also for risk stratification. Innovative biomarkers are studied to improve the sub-phenotyping of HF, to facilitate the diagnosis of HF with preserved ejection fraction, and to tailor therapeutic approaches. The soluble receptor of interleukin 33 (sST2) is one of these new biomarkers. In groups of patients at higher risk of HF (hypertension, diabetes), measurement of sST2 could identify patients requiring more sustained management. In the case of HF with reduced ejection fraction, sST2 would be a powerful marker for risk estimation but also to confirm treatment choice. In the case of HF with preserved ejection fraction, measurement of sST2 may be useful for confirming a diagnosis but also for the risk stratification of the patients and as companion marker for the treatment. Interestingly, the determination of the concentrations of sST2 is facilitated by the evolution of assays with new point of care testing methods. As for many innovative biomarkers, the transition of sS2T to routine testing requires strong multidiscilplinary exchanges with physicians.