This report reviews progress made until the end of 2010 in scaling up access to health sector interventions for HIV prevention, treatment, care and support in low–and middle-income countries. It is the fifth in a series of annual progress reports published since 2006 by the World Health Organization (WHO), United Nations Children’s Fund (UNICEF) and Joint United Nations Programme on HIV/AIDS (UNAIDS), in collaboration with national and international partners, to monitor key components of the health sector response to the HIV epidemic. The report reflects the commitment of United Nations Member States, civil society and United Nations agencies to ensure accountability for global progress in the response to HIV through regular monitoring and reporting. Since 2010 was the deadline established in 2005 for achieving universal access to HIV prevention, treatment, care and support, this report also represents an important benchmark, an opportunity to take stock and identify both achievements and outstanding gaps and to take a constructive look forward in the response at this critical point in the response to the HIV epidemic.