An improvement in governance and increased public participation is widely accepted as one of the most important aspects in the transition toward sustainable development. In Puerto Rico, an island with limited resources and high population density, stakeholder confrontations are becoming more common with varying outcomes. As a response to the government's weak implementation of environmental policy and planning, there are an impressively large number of community/interest groups and non-profit organizations that have become actively engaged in issues related to environmental policy and planning. This thesis analyzes Puerto Rico's environmental policy and participation mechanisms through the perspective of affected citizens and interest groups. It documents and describes the structure and strategies of civil society organizations and how they partake within the institutionalized system of participation and/or work outside that structure. It explores organization's framing of current issues and what these claims and actions portend for the future of civil society activities and environmental policy in Puerto Rico. This study also points to the importance of analyzing policy problems from the perspective of those stakeholders with little access to decision making, and the significance of acknowledging the role of power dynamics on governmental decisions.