Participatory and collaborative forms of public decision-making have gained a firm place in public management, aiming to effectively tackle complex sustainability challenges. Going beyond established mono-dimensional evaluative yardsticks, we assess how and under which circumstances public participation leads to multi-dimensionally ‘successful’ governance outcomes, including environmental, economic and justice-related dimensions. Our data comes from an extensive meta-analysis that synthesizes insights from 300 published case studies of participatory environmental decision-making in 23 countries. We employ two-step QCA that distinguishes between distant (contextual) and proximate (process-oriented) conditions. Results indicate that reconciliatory contexts appear favorable for successful decision-making. Within these contexts, we identified three causal pathways. Together these highlight, apart from the pivotal position of the responsible authority, the role of consensus-oriented collaboration. Characterized by meaningful interaction among participants and consensual decision modes, such forms of collaboration appear as promising mechanisms to balance diverse viewpoints, ultimately leading to successful outcomes in multiple dimensions.