Purpose: The purpose of this study was to evaluate the feasibility and safety of continuous glucose monitoring systems (CGMS) in ST segment elevation myocardial infarction (S-TEMI) patients undergoing primary percutaneous coronary interventions (p-PCI) in coronary care units (CCU). Methods: CGMS was performed for 3 days during CCU hospitalization for each of the subjects. The correlation between glucose values, recorded with CGMS, and finger-stick capillary glucose values was examined. The parameters and safety of CGMS were also investigated. Results: Data from 219 subjects were included in the statistical analysis. Correlation analysis showed a strong positive correlation between interstitial glucose values recorded by CGMS and the corresponding capillary glucose values (P< 0.001). The daytime mean blood glucose(MBG), the nighttime MBG and PT7.8 were the highest in the first day of CGMS compared with the second and third day. Furthermore, there were no indications of major hemorrhage or hematoma at the site of sensor insertion. Any adverse events were mild. Conclusions: CGMS glucose values are relatively accurate and reliable. CGMS were safe and can be used as a tool to detect trends in glucose levels and to predict upcoming glucose excursions in STEMI patients undergoing p-PCI.