Africa faces formidable development challenges in the 21st Century, with expanding populations and accelerating urbanisation; rising demand for water, energy and food; greater hydrological variability predicted with climate change; and persistent poverty and inequalities. Dams seem to promise an appealing package of benefits to meet Africa’s development needs – they can reduce floods, store water for irrigation, provide energy for burgeoning populations and facilitate regional integration. Yet, the benefits and costs of dams are not distributed evenly and new large dams are planned that could alter the political, social and water landscape of the region. What is the role for dams in Africa’s development? Can they give African countries the boost they need for growth and poverty alleviation, or will they only serve to exacerbate environmental problems, conflict and existing inequalities?