An audit of the departmental policy for thromboembolic prophylaxis was undertaken, examining the use of TED stockings, administration of subcutaneous low-dose heparin and inclusion into a multicentre pulmonary embolism prevention (PEP) trial for fractured neck of the femur. The results showed that despite an established unit policy, only 43% of patients undergoing primary hip replacement and 14% undergoing revision replacement received subcutaneous heparin. All patients undergoing primary and revision total knee replacement received subcutaneous heparin, but 75% of these patients received an incorrect dose. Use of TED stockings in patients who had sustained a fractured neck of the femur, ranged from 0% to 70% depending on the type of fixation. Use of subcutaneous heparin in these patients ranged between 0% and 20% and inclusion into the PEP trial from 0% to 20%. The results of this study were presented to the clinicians working in the orthopaedic department and 3 months later the audit cycle was completed by repeating the study. It was found there was a statistically significant improvement in the administration of subcutaneous heparin and in the wearing of TED stockings in the joint arthroplasty group as well as in the inclusion of hip fracture patients into the PEP trial. This study demonstrates that established protocols are of little value unless audited and that completion of the audit cycle is essential. It does not attempt to show that one prophylactic method is better than another.