Since 1992, the Philippines has employed an innovative requirement to demonstrate social acceptability in project planning as a means through which public participation can be established. This paper discusses the participatory mechanisms used and evaluates the effectiveness of public participation in three case studies from key development sectors. In doing so, the existing conceptual frameworks for evaluating public participation are further developed through insights to community empowerment and sustainability in particular. Whilst increased public participation has resulted in improvements in the EIA process and environmental decision making in the Philippines, the evaluation of the case studies also reveals substantial issues of conflict within the communities and of the representation of diverse local interests at core stages in the planning process.