Adolescents (10–19 years) and young people (20–24 years) continue to be vulnerable, both socially and economically, to HIV infection despite efforts to date (WHO, 2013). This is particularly true for adolescents—especially girls—who live in settings with a generalized HIV epidemic or who are members of key populations at higher risk for HIV acquisition or transmission through sexual transmission and injecting drug use. In 2012, there were approximately 2.1 million adolescents living with HIV (2). About one-seventh of all new HIV infections occur during adolescence (Joint United Nations Programme on HIV/AIDS, 2013). Guidance for HTC and on care for adolescents living with HIV (ALHIV) is needed that explicitly considers the range of adolescents’ needs and issues. The World Health Organization (WHO), in collaboration with the United Nations Children’s Fund (UNICEF), the United Nations Population Fund (UNFPA), the United Nations Educational, Scientific and Cultural Organization (UNESCO) and the Global Network of People Living with HIV (GNP+), has developed these guidelines to provide specific recommendations and expert suggestions—for national policy-makers and programme managers and their partners and stakeholders—on prioritizing, planning and providing HIV testing, counselling, treatment and care services for adolescents.