The number of surgical procedures performed is increasing worldwide. In 2004, the number of major operations performed reached 281 million, i.e. approximately one operation per year for every 25 individuals. 1 However, the numbers of complications among surgical patients has also been increasing and this has become the greatest cause of death and disability worldwide. 2 A systematic review has demonstrated that one in every 150 hospitalized patients dies as a consequence of complications related to an adverse event and that almost two thirds of these deaths are associated with surgical treatment. 3 Half of these adverse events are considered to be avoidable. 4 In the 1970s, following a series of air accidents, analysis on these events demonstrated that a combination of stress, fatigue, lack of communication and avoidable errors caused up to 80% of them. 5 Through use of safety checklists and continuous training for crews, the incidence of air accidents has continually fallen since then, despite significant increases in the volume of air traffic. These checklists are now used routinely in aviation and other high-complexity industries. 6 Use of checklists offers a singular opportunity to correct any problems before proceeding and provides awareness of situations that are still to come.Faced with such evidence regarding patient safety, in 2002 the World Health Organization (WHO) adopted resolution 5518 (WHA 55.18), which called on its member countries to strengthen the care taken regarding safety, and demanded standardization of norms in order to construct a culture of surgical safety. Soon afterwards, in May 2004, it launched the campaign "WHO Patient Safety", in which leaders of prominent healthcare institutions, political representatives and patient groups around the world came together with the aim of reducing the numbers of adverse events caused by lack of care for patients.