Malawi, Mozambique, Swaziland, and South Africa have some of the highest HIV/AIDS burdens in the world. All four countries have ambitious plans for scaling-up antiretroviral treatment for the millions of HIV-positive people in the region. In January 2004, we visited these countries with the intention of directly observing the effect of AIDS, especially on health systems, to talk with policy makers and field workers about their concerns and perspectives regarding the epidemic, and to investigate the main issues related to scaling up antiretroviral treatment. We found that financial resources are not regarded as the main immediate constraint anymore, but that the lack of human resources for health is deplored as the single most serious obstacle for implementing the national treatment plans. Yet, none of the countries has developed an urgently required comprehensive human resource strategy. This may also need increased donor attention and resources.