Sustainable development integrates economic development, social development, and environmental protection, with three overarching objectives and essential requirements: (1) poverty reduction, (2) changing unsustainable patterns of production and consumption, and (3) protecting and managing the natural resource base of economic and social development. Integrated water resources management (IWRM) is capable of promoting all three objectives by providing stakeholders with a framework for integrating and coordinating the various aspects of water management in a sustainable and holistic manner. This chapter relates the concept of IWRM to development in the context of the international community's sustainable development paradigm. Though there would seem to be a universal acceptance of the cross-cutting importance of water in development, relative marginalization of water at different levels has taken place because of competing interests. In the ongoing Millennium Development Goals (MDGs), there is only one target dealing specifically with water (drinking water and sanitation) within one of the eight goals (goal 7-ensure environmental sustainability). There is now a call from the water community for the adoption of a dedicated and comprehensive sustainable development goal onwater in the post-MDG follow-up. Some current topics that need to be encompassed by IWRM are succinctly addressed with reference to the recent international developments, including water security, human rights to water, gender equity, implications of climate change, governance, and the water-energy nexus.The ability of making operational the nexus of water with energy, food, health, and ecosystems by thinking "out of the water box" has become critically important.