The purpose of the U.S. Environmental Protection Agency's Office of Research and Development's symposium/workshop entitled, Quantifying Sustainability in Puerto Rico: A Scientific Discussion, was to establish a dialogue between researchers and decision-makers and facilitate research to be used in policy and decision-making. The symposium was designed to discuss sustainability; present ongoing research/work related to the identified issues; discuss what researchers think policy-makers could do to move Puerto Rico toward sustainability, relative to their research; and discuss what was necessary to implement their research island-wide (e.g., data description (spatial and temporal resolution), policy relevance). The subsequent workshop provided participants an opportunity to present what they learned from the talks, how they could use the information, and what was necessary to implement the research into decisions (i.e., what research is needed to fill gaps). Participants included representatives from federal agencies, the Commonwealth of Puerto Rico, academic researchers, and nongovernmental organizations; participants provided expertise from several disciplines.