The phenomenon of cross-generational sex – defined as sexual relationships between an adolescent girl and a partner who is older, usually by 10 or more years – can be linked to many life-long consequences. In the case of girls, premature sex can trap them in an adverse poverty and vulnerability cycle as they may become adolescent mothers; may be forced to leave school; are at risk of entering marriage early to preserve the honour of their family and themselves; and, particularly when having sex with older men, are more exposed to contracting sexually transmitted diseases (STDs), including HIV and AIDS. From a child protection perspective, the power differential between adolescent girls and older – usually wealthier – men is a particular risk factor for abusive relationships, and can be linked to violence. In most cases, these cross-generational relationships become transactional. This study is part of a two-year Oak Foundation-funded programme of work that explores the potential for greater linkages between child protection and anti-poverty work in low- and middle-income countries. It seeks to better understand the multiple and intersecting drivers of cross-generational and transactional sex for adolescent girls in Uganda, to explore some of the consequences adolescents experience and to analyse the extent to which policy and programming are currently addressing the drivers and consequences of this phenomenon.