In South Africa, gender inequalities give men considerable relational power over young women, particularly in circumstances of poverty and where sex is materially rewarded. In this paper, the authors use qualitative interviews and ethnographic observation among 16 young women from the rural Eastern Cape to explore ways young women construct their femininities and exercise agency. The data were collected as part of an evaluation of Stepping Stones, which is a participatory behavioural intervention for HIV prevention that seeks to be gender transformative. The authors findings of multiple and dynamic femininities open up possibilities to reformulate HIV interventions with women that acknowledge existing gender inequalities, validate women's agency, reduce violence and prevent HIV.