Purposes: To investigate the prognostic value of the International Society on Thrombosis and Haemostasis (ISTH) scoring system for overt disseminated intravascular coagulation in emergency department (ED) sepsis and compare the ISTH score with two established scoring systems-the Sequential Organ Failure Assessment (SOFA) score and Acute Physiology and Chronic Health Evaluation Ⅱ (APACHE Ⅱ) score, and two biomarkers-procalcitonin (PCT) and C-reactive protein (CRP).Methods: Septic patients were consecutively enrolled from the ED of an urban university hospital.The ISTH score, SOFA score and APACHE Ⅱ score were calculated, PCT and CRP levels were measured on enrollment.A 30-day follow-up was performed.Results: A total of 680 septic patients were enrolled in this study.The Cox regression analysis showed that the ISTH score had a greater effect on 30-day mortality, and the receiver operating characteristic curve analysis showed that the accuracy of the ISTH score in prediction of 30-day mortality was better than the SOFA score, the APACHE II score, PCT and CRP.Combination of the ISTH score and CRP can enhance the predictive accuracy of 30-day mortality.Conclusions: The ISTH score is a valuable scoring system in the prognosis evaluation in ED sepsis.Furthermore, combination of the ISTH score and CRP can enhance the predictive accuracy of 30-day mortality.