The trend of urbanization in the state of Kerala shows marked peculiarities. Generally, increase in the growth rate of urban population is the result of over concentration in the existing cities especially in metropolitan cities. But in Kerala, the main reason for the growth of urban population is the increase in the number of urban areas and also urbanization of the peripheral areas of the existing major urban centers. With high population densities and the composite primary and tertiary occupational structure in the rural area, the urban characteristics are present even in the rural areas.

The urban sector of Kerala consists of five Municipal Corporations and 60 Municipalities . More than one fourth of the total population of Kerala live in urban areas (25.96%) and this is little less than the national average. Compared to other states the urban- rural system in Kerala have many distinct and peculiar characteristics. The urbanization in Kerala is not limited to the designated cities and towns. Barring a few panchayats in the Hilly tracks and a few isolated areas here and there, the entire state depicts the picture of an urban-rural continuum. In Kerala, it is very difficult to demarcate the urban and rural areas since the features in rural and urban areas are almost alike.

The number of urban agglomerations /towns has increased over the period from 1901 to 2001, but the change from 1991 to 2001 is only marginal. There were 197 census urban towns (65 statutory towns and 132 census towns) in the state in 1991 which decreased to 159 (60 statutory towns and 99 census towns) in 2001. The urban content of the total population of the state has been 18.74% in 1981, 26.4% in 1991 (76.76 lakhs) and 26% in 2001. There are 19 Urban Agglomeration in the State of Kerala, as per 2011 census, which are continuous urban spreads constituting a town and its adjoining urban out-growths, or two or more physically contiguous towns together and any adjoining urban outgrowths of such towns. Ottappalam (UA), Chalakkudy (UA), Kothamangalam (UA), Changanassery (UA) and Kayamkulam (UA) are the five new Urban Agglomerations for 2011 census. The Urban Agglomeration of Vadakara (UA), 2001 census has been merged with Kozhikode (UA) for 2011 census. Similarly Kodungallur (UA) and Guruvayoor (UA) are merged with Thrissur (UA) for 2011 census.

The population of Kerala has increased from 64 lakh in 1901 to 318 lakh in 2001. This growth marks an increase of 10.93 per cent during 1901 to 1911 and 9.28 percent during 1991 to 2001. As per provisional census figures of 2011 the increase in population during the period from 2001 to 2011 is only 5.03% which shows that the rate of growth of population is decreasing. The density of population was 747 persons per sq km in 1991, which increased to 819 persons per sq km in 2001. The density of population varies from the coastal plains to the highland regions, the highest in the coastal land and the lowest in the highland. The share of urban population in Kerala recorded steady growth from 7.11% in 1901 to 26.39% in 1991, but then declined to 25.96% in 2001. But during the last decade the urban population recorded a sharp growth from 25.96% to 47.72% of the population according to provisional census figures of 2011.

In Kerala, urban content has been increasing from 7.11% in 1901 to 26.39% in 1991, but a slight decline seen in the decade 1991 to 2001. This is partially due to the declassification of Pandalam, Piravom, Koothattukulam and Mannarkad municipalities during 1991-2001. The declassification of Eloor and Earattupetta municipalities has not affected urbanization due to classification of the area contained in these municipalities as census towns in 2001 census.