Community development often involves organizing participatory decision-making processes. The challenge is for this to be meaningful. Participatory decision-making has the potential to increase the transparency, accountability, equity and efficiency with which public administration serves the least privileged in society. However, in practice, it often fails to bring about these outcomes. A number of academics and practitioners have, therefore, theorized how participatory decision-making processes can better empower marginalized groups. By critically reviewing this body of work and empirically grounding the debate in recent practice, we aimed to develop a theoretically rigorous, easily applicable and holistic model of an inclusive participatory decision-making process that can work across a range of contexts. The empirical strand included surveying public engagement practitioners and participants about the participatory events they had organized or attended. These empirical findings were combined with insights from the theoretical literature to devise a new conceptual model of emancipatory, inclusive and empowering participatory decision-making – the ‘Tree of Participation’. The model can be useful to both organizers of participatory processes, as a check for empowering and inclusive practice, and to disadvantaged groups, as a set of expectations and demands when engaging in public decision-making.