OBJECTIVES: Diagnosis of patients with dyspnea and suspected acute heart failure (HF) using NT-proBNP testing has been studied internationally. We aimed to analyze the efficiency of NT-proBNP compared to standard clinical evaluation alone use in Spanish Emergency Departments.  METHODS: A decision-analytic model was developed to evaluate the clinical and economic outcomes of both diagnostic alternatives. Model’s time horizon started at patient ED visits and ended after 60 days of follow-up (taking into account differences between hospitalized and non-hospitalized patients). Clinical parameters were mainly extracted from the PRIDE study and were validated by expert opinion (ED and cardiology doctors). We assumed that 65% of patients with dyspnea had HF based on Spanish published data. Resource use was obtained through expert opinion and examined under a National Healthcare System (NHS) perspective. We considered a 900 pg/ml cut-point for NT-proBNP test (sensitivity of 90% and specificity of 85%). Our model compared final diagnostic result with the initial diagnostic before ED discharge. A probabilistic sensitivity analysis was carried out in order to handle uncertainty. RESULTS: Diagnosis using NT-proBNP testing was correct in 91.96% of patients (59.09% true positive cases and 32.87% true negative cases) versus 85.53% with the standard clinical evaluation alone (50.79% of true positive cases and 34.74% of true negative cases). Besides, NT-proBNP testing involved less costs (4,045€ versus 5,405€) mainly due to less hospitalizations and a shorter length of stay. Robustness of results was confirmed through a sensitivity analysis. CONCLUSIONS: NT-proBNP test is less costly per correctly diagnosed patient than standard clinical evaluation alone in the assessment and management of patients with dyspnea at ED rooms from Spanish NHS perspective.