In sub-Saharan Africa, the exchange of sex for material support-labeled "transactional sex" by Western observers--is claimed by some to be a major driver of the AIDS pandemic. Transactional sex is described as akin to prostitution, a degraded form of sexual expression forced on vulnerable women by economic desperation. Using evidence from rural Malawi, we demonstrate that patron-client ties and a moral obligation to support the needy, which are fundamental to African social life, are central elements of transactional sex. We argue that the exchange of sex for money is better understood as one of the many ties of unequal exchange in which Malawians and other Africans engage, an exchange in which the patrons are as important as the clients.