Lack of access to sanitation is not only an affront to human dignity, it pollutes the environment, degrades natural resources, compromises economic productivity, facilitates the transmission of diseases, increases child mortality, jeopardises maternal health, undermines education, exacerbates gender inequalities and perpetuates the cycle of poverty. Despite significant international efforts over the past three decades, lack of access to improved sanitation remains a reality for 2.5 billion people. The repeated failure or reduced efficacy of sanitation projects in the developing world points to the existence of structural barriers and constraints to sanitation which remain poorly understood and inadequately addressed. In response to scholarly recommendations which encourage intentional learning, this thesis explores the structural barriers to, and opportunities for, the implementation of ecological sanitation (ecosan). It also considers the efficacy and prospective sustainability of a range of sanitation strategies designed to manage, overcome or circumvent the barriers, and capitalise on the opportunities. To provide a lens through which to explore these research objectives, an ecosan case study in Funafuti, Tuvalu, was employed. Qualitative research methods, namely semi-structured interviews, field observations, and secondary data analyses were used to investigate how two Global Environment Facility (GEF) projects fostered community acceptance and stimulated demand for composting toilets (falevaties), despite significant social, cultural, political, institutional, economic and environmental barriers to their implementation. The prospective sustainability and replicability of the GEF pilot initiative was also considered from a multiplicity of perspectives, including those of project officials, government workers, members of the community, and representatives from non-governmental and community-based organisations. The findings of this research strongly support the inclusion of sanitation ‘software’. They also highlight the importance of flexible development approaches which reflect local constraints and account for context-specific barriers and opportunities for ecosan. By exposing the difficulty of achieving sustainable sanitation in a place where trade-offs between different facets of sustainability are necessary, this research contributes to scholarly debate around what sustainable sanitation means in practice. It also corroborates the widely promulgated assertion that the GEF pilot project in Tuvalu was successful in achieving community buy-in and engendering behavioural and attitudinal change. However, it raises important questions regarding the prospective sustainability and replicability of the initiative as certain strategies which were employed have the propensity to cultivate dependence and disincentivise community initiative.