This doctoral research attempts to describe and understand the collaborations between very different actors (multinationals, NGOs, national and international public actors) seeking to solve the problem of the pollution of plastic waste in emerging countries (mainly in Africa and Asia). In the context of a transition towards more sustainable and fairer models of production and consumption, plastic waste is a major challenge alongside climate change, poverty and universal access to essential quality services (water, energy, sanitation, etc.). This project stands at the crossroads of several disciplinary fields, i.e. strategic management, international management and sociology. Relying on the theoretical framework of robust action strategies (Ferraro et al., 2015), this doctoral research aims at better understanding inter-organisational collaborations between a wide range of highly diverse stakeholders. Through case studies and experimental methodologies, it will contribute to the literature on societal grand challenges (George et al., 2016), and especially the role of Western multinational companies. It will also identify best practices of collaboration in alliances and projects in order to reduce plastic waste.