Improving access to water, sanitation and hygiene (WaSH) is at the core of the Global 2030 Agenda for Sustainable Development, but achieving this goal depends on the extent to which policy decisions reflect local science and circumstances. We examine the extent to which the WaSH sector is coordinated in Nigeria through interviews, workshops and literature reviews. Findings demonstrate that WaSH related agencies pursue conflicting goals shaped by international agenda, preferences of donors as well as economic and political interests of actors. These and related factors limit the capacity for coordination, innovation and knowledge sharing for evidence-based and home-grown policies