Background: Internationally, the prevalence of hyperglycemia among patients without previously known diabetes in the hospital setting is 7-12%, but Australian data are lacking (1,2). It is important to recognise and follow up hyperglycemia since it is associated with increased mortality and may signify a potential diagnosis of underlying diabetes (1,3). Objectives: To determine the prevalence of hyperglycemia without previously recognised diabetes among all patients screened in the Emergency Department (ED). Secondary aims were to describe the extent of further evaluation for new diabetes via HbA1c testing, adequate glucose monitoring, treatment of significant inpatient hyperglycemia and documented follow-up plans. Methods: Since 2015, all presentations to the ED at a tertiary hospital in Melbourne, Australia underwent screening random plasma glucose (RPG) along with their first plasma biochemistry. RPG in all adult ED presentations was evaluated in a retrospective, cross-sectional study from July to December, 2015. All subjects with hyperglycemia (RPG >7.8 mmol/L) were studied. Pre-existing diabetes was excluded using coding data. Medical records were reviewed to correct for coding errors. A random nested cohort of 200 patients without previously recognised diabetes was further evaluated. Blood glucose monitoring was adequate if undertaken for ≥48 hours. RPG >11 mmol/L was considered significant hyperglycemia and was defined as being adequately treated if supplemental/regular insulin and/or other hypoglycemic agents were charted. Planning of follow-up was considered adequate if hyperglycemia was recognised and a management plan documented in the discharge summary. Results: Prevalence of hyperglycemia in patients without previously recognised diabetes among all patients screened in ED was 5.2% (845/16,268). Of these, 79% required hospital admission and significant hyperglycemia occurred in 15.5%. Within the nested cohort, only 7.5% had follow-up HbA1c. New diabetes (HbA1c ≥6.5% + RPG >11mmol/L) was diagnosed in 20% (3/15) undergoing HbA1c testing. Glucose was adequately monitored in only 9.5%. Appropriate treatment of significant hyperglycemia occurred in only 6.5%. Documentation of a follow-up plan was evident in only 2%. Conclusion: Hyperglycemia is common among patients without previously recognised diabetes presenting to ED. Further evaluation with an HbA1c for new diabetes, performing glucose monitoring, treating significant hyperglycemia in hospital and planning follow-up were suboptimal and require improvement. This is a lost opportunity to diagnose diabetes in those at risk. Reference: (1) Umpierrez et al. J Clin Endocrinol Metab. 2002; 87: 978-82, (2) George et al. Diabetic Med 2005; 22: 1766‐69, (3) Krebs et al. NZ Med J 2000; 113: 379‐81.