This dissertation addresses a conspicuous gap in the fisheries and environmental management literature by presenting a comparative study of the historical, social, cultural, and institutional processes that inform coastal fisheries comanagement in Samoa. In small-scale fisheries across the Pacific, comanagement has emerged as the preferred approach to governance. Comanagement is a collaborative, cross-scale approach that frequently incorporates existing traditional and local institutions and supports shared responsibility and authority between government agencies and local leaders. Comanagement principles also encourage local participation in management and decision-making. While comanagement has produced positive ecological and social results in many settings, there is inconsistency in social outcomes across contexts, with examples of elite capture, the exclusion of marginalized social groups, and the continuation of centralized state control over resources. It is critical to identify and understand the processes and factors that contribute to this inconsistency, in order to create more just and sustainable fisheries management. This dissertation explores the complexity behind participation and power-sharing as drivers and outcomes of fisheries comanagement with a case study in Samoa, where two approaches to resource governance developed in the late 1990’s: the Community-Based Fisheries Management Programme (CBFMP) and the Marine Protected Area (MPA) program. Both employed comanagement principles; however, the CBFMP integrated traditional Samoan institutions and village-scale marine tenure systems to improve fisheries productivity for food security; in contrast, the MPA was designed around larger ecological scales and implemented a new institutional organization that prioritized conservation. Samoa presents a unique opportunity to compare institutional and operational differences between two common forms of coastal marine management in a shared social-ecological context, and to examine the situated factors that contribute to divergent outcomes. Drawing from mixed-methods fieldwork including household surveys, interviews, and participant observation on the island of Upolu, this study uses qualitative and quantitative analytical methods to compare the institutional histories, political processes, community perceptions, and social outcomes of these programs. Mixed-methods are frequently used in comanagement research in order to provide multiple benefits to an integrated study of the perceptions, processes, and outcomes of comanagement (Cinner et al., 2012; Levine & Richmond, 2014). As complimentary methods, combined qualitative and quantitative approaches make it possible to triangulate data, but also to recontextualize the partial knowledge created by each, and produce findings that elucidate the meaning and interrelationships informing actions and behaviors (Nightingale, 2003; Plano Clark, 2016). This dissertation presents data collected in eleven villages, including six active CBFMP villages and five in the designated MPAs, and comparatively analyzed with deductive and inductive methodologies. The dissertation integrates three areas of study: first, it interrogates conceptualizations of participation, power-sharing and equity in natural resource management, especially fisheries comanagement contexts; second, it presents a critical analysis of colonial legacies, traditional institutions, and legal pluralism that inform Samoan coastal comanagement; third, it presents a comparative analysis of local control and participation in current management processes. The integration of traditional Samoan cultural values and institutions and the adaptation of colonial institutions as the foundation of governance significantly determined the adaptive capacity of the programs. Following the 2009 South Pacific Tsunami, the MPA program ceased operations, while the village-centered CBFMP continued to expand. While communities in both programs perceived authority over coastal areas (the gataifale) to reside with traditional village leaders, the CBFMP villages expressed greater self-reliance and local control, and had significantly higher rates of participation in management activities and awareness of fishing restrictions than former MPA villages. The integration of traditional institutions in the CBFMP improved adaptive capacity compared to former MPA villages; however, without external support to facilitate management processes, traditional hierarchies and social obligations shaped participation, resulting in the exclusion of women and young men from formal decision-making, and community perceptions of inequality in management outcomes. Still, marginalized groups can also influence their leaders through traditional, informal Samoan processes of deliberation and consensus-building. The findings of this dissertation demonstrate that while the integration of traditional and local institutions into fisheries comanagement can support program resilience, equitable comanagement requires attention to the internal and cross-scale power hierarchies that inform decision-making processes and the distribution of management benefits and costs.