Highlight • Sepsis is a serious syndrome that interferes with patient homeostasis and has a high mortality rate. To our knowledge, this is the first document of using IL-37 to predict mortality risk in patients with sepsis. • We confirmed that the value of serum IL-37 on admission to predict the 28-day mortality of patients with sepsis was second only to the SOFA score, but higher than the commonly used clinical inflammation markers PCT and Hs-CRP, similar to IL-6.