To evaluate the clinical value of fasting blood glucose (FBG) in the diagnosis of multiple organ dysfunction syndrome (MODS) caused by pulmonary infection in elderly patients with diabetes.Patients over 65 years old with diabetic pulmonary infection admitted to Department of Cadres Ward of Bethune International Peace Hospital of PLA from July 2015 to December 2016 were enrolled. According to the patient's highest FBG level during pulmonary infection, all patients were divided in two groups. The cases whose FBG ≥ 8.83 mmol/L were served as suspicious multiple organ dysfunction syndrome in the elderly (MODSE) group, and those had FBG8.83 mmol/L were served as suspicious non-MODSE group. The incidence of MODSE in suspicious MODSE group and suspicious non-MODSE group was compared. The receiver operating characteristic curve (ROC) was drawn, and the clinical value of highest FBG in the diagnosis of MODSE caused by pulmonary infection in elderly patients with diabetes was assessed.119 elderly patients with diabetes and pulmonary infection were enrolled in the analysis. All patients were male, with age of 76-105 years with an average of (89.41±4.16) years. Among 119 patients, 55 of them with suspected MODSE, 64 of them with suspected non-MODSE. The incidence of MODSE in suspicious MODSE group was significantly higher than that in suspicious non-MODSE group (78.2% vs. 12.5%), with statistically significant difference (χFBG≥8.83 mmol/L, as an indicator reflecting the changes of metabolic function, have a diagnostic value for MODSE caused by pulmonary infection in elderly patients with diabetes.