Evidence based practice is seen to be a vehicle through which nurses can deliver more cost-effective care and improve patient outcomes. Despite this, however, ‘evidence’ does not always appear to influence policy and practice. Routine and traditional practices such as pre-operative fasting protocols seem particularly resistant to change. The research literature which repeatedly argues for reduced pre-operative fasting periods for clear fluids dates back to the 1800s. Current research indicates that the ingestion of clear fluids is safe two to four hours pre-operatively. Despite this evidence, however, pre-operative fasting for clear fluids, even for healthy young adults undergoing elective surgery, still persist for periods of up to twelve hours’ duration. ‘Evidence’ was used in a surgical unit in a private hospital in Sydney to reduce pre-operative clear fluid fasting periods for patients requiring elective bowel surgery. This paper will describe the process of implementation of the reduced fasting guidelines. More specifically, it will detail what was done and how it was done; it will also demonstrate the crucial role of strong nursing leadership in this evidence based change to existing practice.