Recent reports show that between 1990 and 2012, among countries, Nigeria had the highest increase in the absolute number of open defecators. Bayelsa State makes a huge contribution to these numbers as almost 70% of residents lack access to improved sanitation. The adoption of Community-Led Total Sanitation (CLTS) as national policy has improved sanitation in the country, but progress has been slower or non-existent in riverine communities where open defecation persists. In communities where defecation is directly into water bodies evidence of the practice is hidden, which may hinder attempts to trigger community-wide behaviour change. This study evaluates sanitation in two riverine communities of Bayelsa State. It applied qualitative multiple-case methodology using observations, interviews and focus group discussions to explore existing sanitation behaviours. Field notes and interview transcripts were analysed using NVivo and qualitative content analysis. Findings highlight physical, cultural and economic drivers inhibiting the successful implementation of CLTS in riverine communities of Bayelsa State. Findings suggest that to be effective, sanitation interventions in riverine communities, where defecation is predominantly into water bodies, may need to make use of modified tools and also be coupled more strongly with development of supply chains for appropriate sanitation goods and services.