The City of Nairobi started as a railway camp in 1899 and soon became a centre of communication, administration and commerce. In time the town grew in size and function to become the major metropolis in Eastern Africa. Nairobi's current population is about 3.5 million (2005). Between 1979 and 1989 its rate of growth was about 4.5 percent per year. While this has declined from its peak of 7.1 percent between 1969 and 1973, the numbers involved are still high.

This large population continues to pose serious problems for the Nairobi City Council; problems compounded by the rapid parallel increase in population in the outskirts of the City, in both the designated urban / trading centers and in surrounding areas.

A number of peri-urban areas have also developed into major population centres which depend largely on the City of Nairobi for services and employment, a fact usually ignored when planning for City services. It is imperative; therefore, that Nairobi plans for a Greater Metropolitan Area and not just for the area within the administrative boundary of the City of Nairobi.

The period immediately after independence was characterized in particular by rapid growth, creating pressures in housing, community services and physical infrastructure. The city had to commission a new, comprehensive, urban study to lay out its growth strategy up to the turn of the Century. The outcome of this was the Nairobi Metropolitan Growth Strategy in 1973, which consisted of a series of policies related to the major aspects of urban development and the broad physical structure within which these policies could be realized. It was hoped then that the City would maintain a continuous review of policies and structures and adjust them to suit the changing circumstances, but, clearly, this has not happened.