Wastewater pollution is a serious problem in the Caribbean. The Nature Conservancy (TNC) is assessing wastewater management in four island nations—the Dominican Republic, Haiti, Jamaica, and Grenada—to understand the barriers and opportunities for addressing this issue. The assessment focuses on scientific/technological approaches; policy, legal, and institutional frameworks; and stakeholder engagement. This analysis attempts to focus on findings specific to NBS as a wastewater treatment approach from more engineered or “grey” solutions. It is difficult, however, to separate these projects from the overarching geopolitical and socioeconomic barriers to improving wastewater management in the region. The analysis also includes an overview of the perceived and actual barriers to wastewater management improvements, for both NBS and grey infrastructure development. Overall, a comprehensive systems-thinking approach to wastewater management in the Caribbean is needed in order to realize the full potential of NBS to address wastewater management.