The global expansion of access to HIV treatment ranks among the great recent achievements in public health. At the end of 2011, an estimated 8 million people in low-and middle-income countries were receiving ART – a 25-fold increase since 2002. Nevertheless, most low- and middle-income countries are yet to achieve ‘Universal Access’ to ART. Reasons for this include lack of awareness of HIV status, high cost of ART, late initiation of ART, human rights issues affecting people living with HIV and key populations and substantial attrition in the ‘test-treat-retain’ continuum. Addressing structural barriers, reducing costs and strengthening the continuum of care is critically important if the full gains of expanded HIV treatment are to be realised.