All of the world's fasting growing cities are located in the developing world. This article focuses on Delhi, with half a million new inhabitants each year, reviewing its history, and exploring the themes of planning, housing, employment, and the environmental impact of a mainly poor and rapidly growing population. The discussion is supported by current data and visual material, and outlines some of the solutions to problems being adaopted by the Development Authority. The paper concludes that the conditions experienced in Delhi are reflective of the situation in India's other mega-cities.