Background: Diabetes is considered a major epidemic of the 21st century. Usually, diabetes begins asymptomatically and the diagnosis takes place an average of 8–12 years after the onset of dysglycaemia. Blood check for glucose is taken at different medical setting, whether at the fasting condition or randomly. Previous studies had shown that abnormal blood glucose predicts future diabetes. Hence, medical staff should consider taking reasonable actions in patients with abnormal blood glucose. Objective: To assess the prevalence of hyperglycaemia in patients presenting to the Department of Emergency Medicine (DEM) with no known history of diabetes, and to evaluate how often were they recommended following this up as an outpatient by the medical staff. Design: A cross-sectional study examined the medical records of adult patients referred to the DEM during 1 November 2011–31 January 2012. Participants: Patients with random blood glucose ≥140 mg/dL and no known history of diabetes were included in the study. The discharge letter was examined for the presence of instructions to conduct further follow up. Key results: A total of 16 784 patients presented to the DEM. of these, 402 patients (2.4%) without known diabetes were hyperglycaemic, 346 patients had blood glucose levels ≥140 mg/dL and 56 patients had blood glucose levels above 200 mg/dL. Only 35 of the 402 included patient files (8.7%) contained instructions for further investigation. There was no statistically significant difference between those who received a letter for further follow up compared with those who did not receive it with respect to age, sex or blood glucose levels. Conclusion: Over 2% of patients who presented to the DEM were hyperglycaemic, without a prior diagnosis of diabetes. A small per cent was recommended to have outpatient follow-up. This represents a missed opportunity for earlier diagnosis of diabetes and emphasised the need for raising medical staff awareness concerning abnormal blood glucose and its implication.