Background and Objectives: The aim of this quality improvement project was to decrease the percentage of emergency department (ED) patients admitted with blood glucose (BG) level above 250 mg/dL to less than 20%. Methods: A work group comprised physicians, pharmacists, and endocrinologists collaborated to standardize management of ED hyperglycemia. Plan-Do-Study-Act cycles included education, monitoring of patients with BG level above 200 mg/dL, and development of an ED-specific insulin protocol. Results: Following the initiative, 24.8% fewer patients were admitted with BG level above 250 mg/dL. The average admission BG level was reduced by 65.8 mg/dL, creating a significant shift toward improved average BG level. No difference was seen in hospital mortality, hospital length of stay, ED length of stay, hypoglycemia, or inhospital diabetic ketoacidosis or hyperglycemic hyperosmolar syndrome. Conclusion: Implementation of a standardized hyperglycemia treatment protocol along with pharmacist interventions reduced average admission BG and the percentage of patients with BG level above 250 mg/dL on admission.