Current studies are debating on the association of higher admission blood glucose (BG) and increased mortality of acute coronary syndrome (ACS). This study evaluated association of mortality between admission BG and BG control in 222 patients with ACS who received coronary intervention in the intensive care unit. This study observed medical records through electronic medical record retrospectively and evaluated all patients who were admitted for the first attack of ST-segment elevation MI (STEMI), non-STEMI, and unstable angina pectoris. Admission BG higher than 220 mg/dl was statistically significantly associated with lower survival in patients; the association was stronger than in patients with admission BG higher than 140 mg/dl to less than 220 mg/dl and patients with admission BG less than 140 mg/dl (Wilcoxon test, p = 0.002). Survival time after admission was also associated with the history of diabetes mellitus (DM). Patients with diabetes had significantly lower survival than those without diabetes (Wilcoxon test, p = 0.028). Survival after ACS was not consistent with each insulin intervention of on admission to 6, 24, and 48 h after admission. There is a statistically significant association between admission BG higher than 220 mg/dl and low survival but each intervention of post admission BG levels were not consistently associated with the mortality. Additionally, history of DM is associated with lower survival in patients with ACS on admission.