Urbanisation is the process by which large number of people becomes permanently concentrated in small areas forming cities. The definition of a city or an urban area changes from time to time and place to place. The United Nations Organisation has recommended that member countries regard all places with more than 20,000 inhabitants living close together as urban; but, in fact nations compile their statistics on the basis of many different standards. United States, for instance, uses “urban place” to mean any locality where more than 2,500 people liveGoa is the most urbanised among the states with almost one half of its population living in urban areas. The least urbanised state is Himachal Pradesh (9.3 per cent) and the least urbanised Union Territory is Dadra and Nagar Haveli (22.89 per cent). Urbanisation is considered beneficial because of better opportunity for earning higher incomes, better infrastructure and better awareness and response of people to social issues in general. Urabanisation thereby contributes to modernisation and social change. The birth rate, the death rate, IMR and fertility rates are lower in urban areas than in rural areas. However, urbanisation is not an unmixed blessing. Shortage of land, the growing gap between the demand and supply of basic facilities and services (e.g. housing, water supply, sanitary services, electricity, roads, public transport, etc.) and finally, massive environmental pollution in cities, adversely affect the quality of urban life.