Since the beginning of the city, slums have been a part of Bombay's landscape. However, the first official enumeration of the population living in slums was performed only in 1976. It found 2.8 million people in 1,680 settlements all over Bombay. The total population was then 5.9 million.
A second count in 1983 found 1,930 settlements. They contained 4.3 million people in 924,572 households. The number of people living on pavements was estimated to be 700,000. These two populations accounted for about half of Bombay's citizens.
Recent estimates claim that about 40% of the city's population live in 3.5% of its area. The population density in these enclaves then come out to be 400,000 persons per square kilometer! On the other hand, the 1991 census calculates a density of 16,400 persons per square kilometer in the slums of Bombay.
These numbers do not capture the human cost of slums, they give only an idea of the magnitude of the problems of low-cost housing in urban India.
In the 19th century slums grew around the mills and other places of employment. Now they grow in any empty space. Although older slums in Byculla, Dharavi and Khar were initially separate villages, with their own traditional industries, most people who live in slums work outside them.
| fraction of slums | on land owned by |
| 50% | Private |
| 18% | BMC |
| 16% | State government |
| 9% | Maharashtra Housing Board |
| 6% | Central government |