"Medicine today has entered its B-17 phase. Substantial parts of what hospitals (do) ....... are now too complex for clinicians to carry them out reliably from memory alone." 6. In January 2007 the World Health Organization (WHO) began a programme aimed at improving the safety of surgical care globally. The initiative, called "Safe Surgery Saves Lives" aimed to identify minimum standards of surgical care that could be universally applied across countries and settings. One component of the initiative was the introduction of a peri-operative checklist.1. In February 2009 the National Patient Safety Agency (NPSA) issued an alert requiring all hospitals in England and Wales to implement the peri-operative checklist by February 2010.2 The main reason for the checklist is to improve patient care by making the operative environment a safer place. But why the need for this checklist and how can it help? What evidence exists that it makes any difference to patient care? What are the essential component parts to the checklist and how can is it introduced? We hope to answer these questions for you in the following text.