The gender-based response to HIV in sub-Saharan Africa has tended to reinforce normative stereotypes of women as subordinated, passive and powerless victims, in particular in sexual relations. However, based on qualitative data from Rwanda, this paper argues that such conceptualisations fail to recognise that while women do comply with prevalent social norms, they also challenge these norms and sex becomes a domain in which they can exert power. Female sexuality and sexual gratification - acknowledged and valued by women as well as men - play a pivotal role in the Rwandese mode of sexual intercourse. This provides women a central position in sexual relations, which affords them sexual power. Recognising their sexuality as a resource and drawing upon this 'sexual capital', women are active social agents who have the capacity to manipulate and challenge male dominance in a deliberate strategy both to practice safer sex and to access decision-making power and material resources. This suggests that inherent in sexual relations is a potential for the empowerment of women and the transformation of gender relations.