This paper analyses the interdependency of water and energy in India’s wastewater sector. Wastewater treatment plants consume a great deal of energy. Energy-efficient technologies are available, but are only spreading slowly in developing countries. In India, only 10% of all wastewater generated is treated, while energy demand is soaring. The case for investments in energy-efficient solutions thus seems clear. This case study analyses under which conditions and with which instruments integrated approaches to the water, energy and food (land) sectors (WEF-Nexus) are useful in various different wastewater systems across the country. It focuses on the identification of existing drivers of and barriers to the diffusion of energy-efficient technologies in India’s urban wastewater sector, uncovering how investments in resource- and lifecycle-oriented solutions could be enhanced. Key findings are that India’s urban wastewater sector is still largely in a situation of lock-in although first innovative initiatives that focus on more resource footprint, lifecycle-oriented approaches exist in some niches.