In many low- and lower-middle-income countries, key barriers to girls’ secondary school access and learning include poverty, school inaccessibility, poor school quality and lack of gender-sensitive practices in the classroom. The non-governmental organisation, Campaign for Female Education (CAMFED), provides a range of financial, pedagogical, and community-supported interventions aimed at removing these barriers in government secondary schools in Tanzania and Zimbabwe. Using longitudinal data, we adopt quasi-experimental methods to examine the impact of the CAMFED programme on reducing secondary school dropout and improving test scores in English and mathematics. Results suggest that the CAMFED programme has a significant effect on both improving access and learning for the most disadvantaged adolescent girls. However, low-performing learners remain particularly at risk of dropout, necessitating further consideration and support for these girls.