Objective: The aims of the present study were to evaluate the prognostic value of adrenomedullin (AM) in septic patients in the emergency department (ED) and to compare it with procalcitonin (PCT) and Mortality in Emergency Department Sepsis (MEDS) score.Methods: We enrolled 837 consecutive patients who fulfilled the systemic inflammatory response syndrome (SIRS) criteria and were admitted to the ED of Beijing Chaoyang Hospital and 100 age-matched healthy controls.Serum AM and PCT were determined, and MEDS score was calculated at enrollment.The prognostic value of AM was compared with PCT and MEDS score.Primary outcome was in-hospital mortality.Results: On admission, mean levels of AM were 28.66±6.05 ng/L in 100 healthy controls, 31.65±-6.47 ng/L in 153 SIRS patients, 33.24±8.59 ng/L in 376 sepsis patients, 34.81±8.33 ng/L in 210 severe sepsis patients, and 45.15±9.87 ng/L in 98 septic shock patients.The differences between the two groups were significant.AM level was higher in non-survivors than in survivors in every group.The area under receiver operating characteristic curve (AUC) of AM for predicting in-hospital mortality in septic patients was 0.773, which was better than PCT (0.701) and MEDS score (0.721).Combination of AM and MEDS score improved the accuracy of AM and MEDS score in predicting the risk of in-hospital mortality (AUC=0.817).In logistic regression analysis, AM and MEDS score were independent predictors of in-hospital mortality.Conclusions: Adrenomedullin is valuable for prognosis in septic patients in the ED.