Participation procedures that do not address existing power relations among actors can preserve or exacerbate injustice and put those already socially marginalised in a more disadvantaged position in environmental management. This paper therefore explores the role of intermediary actors in establishing procedural justice grounds for meaningful participation in environmental impact assessments (EIAs). It also examines the extent to which Indonesia's EIA supports legitimate and accountable representation by NGO intermediaries, thereby helping to achieve procedural justice in the practice of EIA. The findings highlight the procedural justice goals that are discernible through Indonesia's EIA regulatory framework. Three EIA commissions and two village case studies exhibit different interpretations of the meaning and implications of legitimacy regarding representation by NGOs in the EIA decision-making process. In the case studies, instances of land-use conflicts demonstrated concerns over NGO's accountability, resulting in the perception of “unjust” participation by the research participants. This paper suggests that more attention should be paid to conceptualising the value and implications of accountability and legitimacy, which will support the representation of intermediaries in EIA and create a more meaningful and just public participation process.