Data on the cost-effectiveness of HIV prevention in sub-Saharan Africa and on highly active antiretroviral therapy (HAART) indicate that prevention is at least 28 times more cost effective than HAART. We aim to show that funding HAART at the expense of prevention means greater loss of life. To maximise health benefits, the next major increments of HIV funding in sub-Saharan Africa should be devoted mainly to prevention and to some non-HAART treatment and care. Funds should be allocated to HAART primarily for demonstration projects that will help prepare for scaled-up HAART provision following broad population coverage by prevention programmes. UNAIDS and the London School of Hygiene and Tropical Medicine recently estimated that at least US $9.2 billion annually is required to mount an appropriate response to the HIV pandemic, including substantial funding for HAART. To date, US $1.96 billion has been committed to the newly-established UN Global Fund to Fight AIDS, Tuberculosis, and Malaria. It is a moral imperative that expanded programmes to control HIV be implemented without delay, and that the goal of US $9.2 billion or more in annual spending be attained as rapidly as possible. The findings and recommendations of this analysis pertain to the phasing in of additional HIV-related activities during the current period of improved but inadequate funding.