OBJECTIVE: Model the feasibility and affordability of the 2001 UN General Assembly Special Session on AIDS goals to reduce mother-to-child transmission of HIV (MTCT) by 50% by 2010 and achieve 80% coverage of interventions to reduce it among women presenting for antenatal care. METHODS: The cost and human resource needs of prevention of MTCT (PMTCT) and paediatric treatment were modelled for 2007-2015 and compared with the AIDS budgets and available health workforce in Burkina Faso, Cameroon, Cote d'Ivoire, Malawi, Rwanda, United Republic of Tanzania, and Zambia. Interventions used were promotion of family planning to people living with HIV, HIV testing and counselling, antiretroviral treatment to prevent MTCT and for HIV-infected children, and cotrimoxazole prophylaxis for mothers with advanced HIV infection and HIV-exposed children. RESULTS: The cumulative cost from 2007 to 2015 of the intervention in the seven countries combined amounted to US$587 688 291, 86% for PMTCT and 14% for paediatric treatment. Three out of the seven countries - Rwanda, Zambia, and Burkina Faso (almost) - were predicted to have sufficient AIDS funding, but only one - Zambia - was predicted to have also sufficient human resources to scale up the interventions by 2010 and sustain them up to 2015. The cost-effectiveness would be less than US$1150 per infection prevented in fully scaled-up programmes. CONCLUSION: Scaling up PMTCT will require more funds than currently available in many countries, but human resources appear to be a greater bottleneck than funding. We suggest that human resource capacity be assessed when increased funds for PMTCT are requested.