Gaborone is one of the fastest growing cities in Sub-Saharan Africa. Today, the urban agglomeration of the capital of Botswana has only about a quarter million inhabitants, but will become a half-million city in only two decades. Thus, Gaborone is facing the challenge of the typical problems of mega-cities, such as environmental degradation, urban sprawl. The reseach project DIMSUD is dedicated to identify ways toward sustainable urban development. Starting from an analysis of the challenges for in Gaborone, tasks for urban planning and opportunities for sustainable urban development are shown.