Emergency medicine represents a unique practice environment where diagnostic accuracy, treatment, and critical disposition decisions must occur in a time-sensitive environment intolerant of both errors and inefficiency. These pressures can make an accurate heart failure diagnosis challenging, as it must be predominately based on clinical findings. Although accuracy is improved by natriuretic peptide testing, at some point in the clinical course a disposition is required regardless of diagnostic certainty. Disposition options range widely from expensive and highly specialized intensive care unit admissions to low-tech/low-cost observation management or even discharge directly to home. In this vein, success is predicated on matching patient needs to available resources while minimizing the untimely discharge that results in a return visit to the emergency room. Thus, the role of the emergency physician is to predict the future based on limited objective data. Biomarkers may aid in this task, and the newly available galectin-3 assay may be of particular utility. Elevated galectin-3, reflective of myocardial fibrosis and inflammation, is associated with increased risk of short-term death and the necessity for 30-day rehospitalization. The availability of accurate risk stratification tools for predicting the probability of rehospitalization or death could guide in the matching of resource-intensive heart failure disease management efforts to the higher risk cohort, while simultaneously identifying lower risk candidates for successful observation unit or outpatient management. This article reviews the potential utility of galectin-3 measurement for use in emergency department decision making.