The administration of prophylactic antibiotics is essential in the prevention of surgical site infection, particularly when metalwork is implanted. Intravenous Cefuroxime has been the antibiotic of choice for prophylaxis in our unit over the last few years. Unfortunately this has been linked to an increased rate of Clostridium Difficile infection. Our departmental antibiotic prophylaxis guidelines, based on the Scottish Intercollegiate Guidelines Network (SIGN), were therefore revised, such that intravenous Flucloxacillin and Gentamicin became the first line agents. We primarily aimed to assess whether prophylactic antibiotics were being administered according to our revised local guidelines. Steps were then taken to improve adherence to the guidelines, and the audit repeated. Data was collected prospectively between 1st November 2010 and 28th November 2010 (cycle 1). Demographic data, type of surgery, details of choice, dose and timing of antibiotic administration were compiled. The quality of documentation was also reviewed. Interventions to improve adherence to the guidelines were commenced between 1st January 2011 and 28th February 2011. This included a departmental presentation, supplementary distribution of the guidelines and email communication to all orthopaedic surgeons and anaesthetists to increase awareness. A repeat audit cycle was performed between 1st March 2011 and 28th March 2011 (cycle 2). All data was stored and statistically analysed using SPSS for Windows 17.0. A total of 130 patients were included, with 65 patients in each cycle. Demographic data and type of surgery were reasonably similar in both cycles. Intravenous antibiotics, when required, were administered within 30 minutes of the surgical incision in most cases in both cycles of the audit. In the first cycle of the audit only 9 out of 65 patients (14%) received the correct antibiotics as suggested by our updated guidelines. This improved significantly to 46 out of 57 patients (81%) in the second cycle. Documentation of antibiotic prescribing in the anaesthetic record, operation note and drug charts also improved in the second cycle. We observed poor initial adherence to our updated guidelines as most patients received incorrect antibiotic prophylaxis. However, following our audit interventions to increase awareness of the new guidelines, we witnessed a significant improvement in compliance. Our next step will be to ensure that the new policy of using intravenous Flucloxacillin and Gentamicin does indeed reduce the rate of Clostridium Difficile infection while maintaining a low rate of deep and superficial wound infection.