||Healthcare associated infection affects hundreds of millions of people worldwide in developed, transitional, and developing countries and is a major global issue for patient safety. It complicates a significant proportion of patient care deliveries, adds to the burden of resource use, and contributes to unexpected deaths. Whether acquired during home, ambulatory, institutional or hospital care, health care-associated infections (HAIs) constitute one of the greatest challenges of today’s medicine. According to the Institute of Medicine, hospital-related adverse events in the United States, including HAIs, are responsible for 44,000 to 98,000 deaths annually and represent a cost of $17 to $29 billion. Among these, HAIs now concern 5-15 per 100 hospitalized patients and can lead to complications in 25-50% of those admitted to intensive care units. In the United Kingdom, HAIs cost around £1 billion a year and contribute to at least 5000 deaths. Importantly, these estimates only concern infections acquired in acute-care hospitals and ignore those resulting from ambulatory care or acquired in other settings. Infection rates are higher in transitional and developing countries than in developed countries. Worldwide, HAIs affect as many as 1.4 million patients at any point in time in healthcare institutions. The World Health Organization (WHO) supported the creation of an international alliance to improve patient safety as a global initiative and the World Alliance for Patient Safety was launched in October 2004. The six actions areas of the Alliance are: Patients for Patient Safety; Taxonomy; Research; Solutions for Patient Safety; Reporting and Learning; and a biennial Global Patient Safety Challenge. HAI is the topic chosen for the first Challenge, covering 2005-2006, and The Global Patient Safety Challenge Clean Care is Safer Care was launched in October 2005. It embraces existing WHO strategies to reduce HAI and also creates the momentum for new actions to improve hand hygiene during patient care. The major objectives of Clean Care is Safer Care are: to raise awareness of the impact of HAI on patient safety and promote preventive strategies within countries; to build commitment from countries to priorities reducing HAI; and to test the implementation of the new WHO Guidelines on Hand Hygiene in Health Care in specific districts worldwide as part of an integrated package of actions derived from existing WHO strategies in the fields of blood safety, injection and immunisation safety, clinical procedure safety, and water, basic sanitation and waste management.