Although India has the second largest urban population in the world and a large slum population, data on slums was not available till the 2001 Census. The Registrar General of India enumerated slum population for the first time in 2001, and that too only for 743 towns and cities.

Only 640 towns and cities were reported to have any slum out of the total 5161 towns in India in 2001. In the 2011 Census data on slums was collected from 4041 cities and towns, and only 2542 reported having any slum, with a slum population of about 68 million.

The Pronab Sen Committee, constituted by the Planning Commission in 2010, had estimated the slum population at 93 million. UN Habitat, in 2006, put the number at an estimated 170 million.