Objective To determine the effect of pre-operative blood glucose level on the incidence of contrast-induced nephropathy (CIN) in patients with ST-segment elevation myocardial infarction undergoing urgent percutaneous coronary interventions (PCI). Methods A total of 745 ST-segment elevation myocardial infarction patients undergoing urgent coronary interventions in our department from October 2008 to May 2012 were enrolled in this study. All patients received low osmolar nonionic contrast media. Renal function was evaluated by serum creatinine concentration at baseline and each day for the following 3d to analyze the effect of pre-operative glucose level on the incidence of CIN. Results Among the 745 patients (530 males and 215 females), there were 156 patients having CIN, with an incidence of 20.9%. There was no significant difference in the age, diabetes mellitus, high sensitivity C-reactive protein (hs-CRP), blood glucose level, left ventricular ejection fraction (LVEF), and reperfusion time between the CIN and non-CIN groups (P＜0.05). The patients from the CIN group had significantly higher risk of in-hospital all-cause mortality, cardiac death, and arrhythmias (P＜0.05). Multiple logistic regression analysis showed that blood glucose, hs-CRP, and LVEF were independent risk factors for CIN. Elevated glucose level as variables categorized into quartiles were independently correlated with the development of CIN (P＜0.05). Conclusion Elevated pre-operative glucose level has a close correlation with the development of CIN in patients with ST-segment elevation myocardial infarction undergoing urgent PCI, and increases in-hospital mortality as an independent risk factor for CIN.