- The relationship between livelihoods and forest use is one of the main challenges facing wildlife and habitat conservation in developing countries. Poor residents in forest-adjacent areas are typically perceived to be the main forest users, with use often deemed illegal. However, there is still a limited understanding of livelihood constraints of the poor, and how such constraints influence illegal forest use, particularly for poor residents in forest-adjacent communities. In this paper, we address this gap. First, the measures for livelihood constraints, including food access constraints and education constraints, and illegal forest use are proposed. Second, the developed measures are used in a structural equation model, to explore the relationship between livelihood constraints and illegal forest use, for poor residents in communities adjacent to Volcanoes National Park, in Rwanda. Food access constraints, a dimension of food security constraints, were found to be the strongest predicator of illegal forest use. However, food insecure residents around the park may not be the main driver of current levels of illegal forest use, supporting previous research questioning the narrative of poverty driven illegal forest use in developing countries.