INTRODUCTION. Hyperglycaemia during hospitalisation is associated with a longer and more complicated admission and with increased mortality. Therefore, guidelines suggest that blood glucose should be less than 10 mmol/l. In this audit, we aimed to describe the prevalence of diabetes patients at four orthopaedic departments in the Capital Region of Denmark and to measure the quality of in-hospital diabetes management. METHODS. We conducted audits of medical records in the electronic health record system for two months in 2019. All patients admitted were included in the audit. We gathered information on diabetes status, orthopaedic diagnosis, glycosylated haemoglobin and diabetes management. RESULTS. Among 2,463 included patients, 10% had diabetes. The three most frequent diagnosis groups were infection, fracture of lower extremity and hospitalised for alloplastic surgery. The number of blood glucose measurements during 24-hour perioperative care was 6.5. Among patients analysed, 10-20% did not have their blood glucose measured in the days following surgery. Among patients, 64% received insulin 1-50% of the required times. CONCLUSION. We demonstrated that 10% of hospitalised patients suffer from diabetes. The audit also showed that blood glucose is generally measured according to guidelines, whereas the treatment of an elevated blood glucose is far from being given according to guidelines. This may potentially delay recovery and prolong hospitalisation. FUNDING. none. TRIAL REGISTRATION. not relevant.