Some researches suggested that combined use of the scoring systems and biomarkers might supplement each other.We evaluated the ability of the Mortality in Emergency Department Sepsis (MEDS) score to predict severity of sepsis and 28-day mortality of patients, and compared with the biomarkers procalcitonin (PCT), interleukin-6 (IL-6), and C-reactive protein (CRP).In order to find a better method for evaluation of ED patients with sepsis, we combined the MEDS score with relevant biomarkers.501 adult ED patients with sepsis were selected for this prospective clinical study.The MEDS score was recorded, PCT, IL-6 and CRP were measured.First, all cases were divided into sepsis group and severe sepsis and septic shock group.Second, all patients were separated into survivors and non-survivors groups by the 28-day outcomes.Receiver operating characteristics (ROC) curves were used to assess the predict ability of these variables.A logistic regression model was employed for establish the optimal combination.The MEDS score, PCT, IL-6, and CRP were all statistically different in the comparison of sepsis group (319 cases) and severe sepsis and septic shock group (182 cases), and same difference was found between survivors (367 cases) and non-survivors (134 cases).Areas under the curves (AUC) of MEDS score and PCT, IL-6, CRP were for severity of sepsis were 0.793, and 0.712, 0.695, 0.681, respectively, and for mortality of 28-day were 0.773, and 0.681, 0.692, 0.661, respectively.When combined with the MEDS score, only PCT was an independent predictor of 28-day outcomes.The new combination of MEDS score with PCT improved AUC both in the severity of sepsis (0.852) and in the mortality of 28-day (0.823).Moreover, the new combination for severity evaluation had better sensitivity (63.1%), specificity (92.2%), PPV (81.3%) and NPV (80.1%).The predictive ability of the MEDS score on the severity and 28-day mortality of septic ED patients is effective, and better than that of biomarkers such as PCT, IL-6 and CRP.The application of MEDS score combined with PCT enhanced the predictive ability significantly, and particularly in distinguished severe sepsis and septic shock from sepsis.