This third edition of the 'Recipe Book' seeks to bridge the gap between audit and improvement, by providing anaesthetists with an introduction to the science of improvement and demonstrating some basic tools which can be used to drive positive patient centred change. A number of anaesthetists and intensivists throughout the UK have now learned improvement methodology, often from participation in one of the national or regional patient safety programmes. We have therefore included a number of examples from practising clinicians illustrating how they have identified problems using audit methodology, and then applied simple improvement techniques to achieve change.