Transfrontier Conservation Areas (TFCAs) were created to achieve the promotion of biodiversity conservation while at the same time offering better living conditions for local residents, most of them struggling to live from subsistence agriculture in semi-arid savannas. In addition, local communities bear most of the costs of conservation while getting few of the benefits. While substantial means are invested into biodiversity conservation in TFCAs, too little is invested in the development and well-being of local communities, compromising the health of both social and ecological systems in the long term. The ProSuLi project engaged with four communities living in two TFCAs in three countries (Botswana, Mozambique and Zimbabwe) to identify, co-design, implement and monitor interventions that could improve and diversify livelihoods and, at the same time, manage natural resources. The approach was transdisciplinary, demand-driven and fully participatory, as the project activities were designed by TFCA residents, the final beneficiaries, promoting more environmental justice. Technical support was provided by postgraduate students, senior researchers and other private, governmental and non-governmental institutions. The project's hypothesis was that collective action supported by targeted capacity building and co-designed governance systems could result in a better appropriation of one's livelihood and more sustainable use of natural resources for the benefit of the whole social-ecological system.