This important research emphasises that many governments are not meeting spending goals, and in many countries the financing gaps are so great that, even if they met the spending goals, expenditure would still fall short of what is needed (expenditure would cover only 64% of estimated future funding requirements, leaving a gap of around a third of the total US$7·9 billion needed). Quantification of the gaps in domestic spending encourages us to consider whether the amount of funding is appropriate and how much more could and should be done to fight HIV/AIDS. The important question of how governments make allocation choices also comes to the forefront. The aim of this Comment is to draw attention to the many dimensions that contribute to the complexity of these decisions on health resource allocation.