When the leaders of the world's largest industrial nations meet in Scotland, they will debate how to address the HIV/Aids crisis and whether to significantly increase assistance to Africa. But for the summit to have a real impact on the Aids pandemic, the G8 will have to do more than increase funding; they will have to address the economic and social realities that make women and girls a special, high-risk group. Evidence from Africa shows the importance and cost-effectiveness of this strategy.