This summary report presents the findings of the Bangladesh WASH Poverty Diagnostic (BWPD) study led by the World Bank's Water and Poverty Global Practices. Though very few Bangladeshis now fetch water from rivers or defecate in fields, the vast majority still live in environments plagued by inadequate water supply, sanitation, and hygiene (WASH) that hinder the country's overall development. BWPD is a data-driven exercise with an objective to highlight the key inadequacies in WASH service delivery and guide country and sector priorities for maximum impact during the Sustainable Development Goal era. BWPD gives a snapshot of the quality and inequality of WASH access by generating statistics from numerous datasets. BWPD also attempts to show the implications of these numbers on human development and poverty reduction. A large portion of the work is dedicated to presenting stylized facts on the synergies between different dimensions of WASH and human development outcomes such as in health, nutrition, and education. Further, the generated numbers should help government and other stakeholders identify gaps in service delivery and ask questions on why these gaps exist. The final portion of this study begins a discussion on the institutional challenges that could be inhibiting high-quality service delivery. The report concludes by offering recommendations for moving Bangladesh's WASH sector forward.