In 2004, the World Health Organisation's Department of HIV/AIDS and the UK Department for International Development (DfID) supported the Safe Passages to Adulthood programme to develop a joint publication entitled HIV/AIDS prevention and care for especially vulnerable young people: a framework for action. This offers a straightforward guide to priority setting, outlining five core principles underpinning effective HIV/AIDS prevention programming with young people. While of relevance to work with young people in general, these principles establish a framework within which to meet the needs of especially vulnerable young people. The five principles are: Putting the young person first; Promoting meaningful participation; A commitment to rights; Promoting gender equity; and Tackling risk and vulnerability. This follow-up publication is intended to be read in conjunction with HIV/AIDS prevention and care for especially vulnerable young people: a framework for action. It describes programmes in Argentina, Nigeria, Iran, India and Kenya whose work with especially vulnerable young people illustrates some or all of these five principles in action.