This chapter examines women’s empowerment in a rural WASH (water, sanitation, and hygiene) intervention in Vietnam (the Vietnam Project) through the Capability Approach, focusing on the role of the Vietnam Women’s Union (VWU) in WASH service delivery. It critically interrogates performance indicators that equate empowerment with women’s presence in leadership positions, showing how such measures obscure the distinction between pre-existing institutional roles and genuine capability expansion. Drawing on mixed-methods data from surveys, interviews, and focus groups with VWU staff, community leaders, and household members, the chapter analyses empowerment through three determinants of capability change: effective access to training and resources, effective agency in WASH mobilisation and leadership, and socio-structural contexts. The findings show that while participation enhanced women’s skills, confidence, and social recognition, unpaid labour, gender norms, political gatekeeping, and household responsibilities constrained the conversion of participation into economic autonomy and formal power. The chapter argues that women’s empowerment in WASH requires not only inclusion in service delivery but transformation of the institutional and normative conditions that shape women’s real freedoms to lead, decide, and act.