BACKGROUND Studies conducted in several sub-Saharan African countries have revealed that women and girls engage in intergenerational sexual relationships without the protection of condoms, giving cause for concern about HIV transmission. These relationships often occur against the girls' will and for many reasons, including reasons associated with subsistence. However, some young women do act as active social agents who rationally engage in intergenerational sexual exchanges oriented towards consumption. The present study examines the dynamics of intergenerational sexual relationships among schoolgirls in Botswana. METHODS In-depth interviews were conducted with 15 schoolgirls who were currently in an intergenerational sexual relationship. The social, cultural and economic factors that cause young girls to engage in these relationships and how intergenerational sex contributes to unsafe sexual practices were examined. RESULTS The findings revealed that not all girls were passive and controlled by their older sexual partners. Some derived pleasure, enjoyment, love and equal partnership in these sexual relationships. They displayed a capacity to take charge of their own sexual lives by insisting on and engaging in safe-sex behaviours. Another set of girls had little or no decision-making power. Their relationships with older boyfriends were characterised by coercion and manipulation. Negotiation for condom use was difficult for this group. CONCLUSIONS Effective policy and practice can be informed by the findings, leading to a reduction in HIV transmission as a result of intergenerational sex. In particular, the study has drawn attention to girls who are able to assert themselves within intergenerational sexual relationships and successfully negotiate safe sex. These strategies can be incorporated in programs to assist girls who face challenges and difficulties in negotiating safe sex with older men.