Vegetation is an important component of any ecosystem. In urban areas, presence of vegetation is essential for reducing the effects of environmental pollution and maintaining the ecological balance. In the wake of excessive growth of population, the urban vegetation with parkland, especially in developing countries, are diminishing rapidly to provide additional space to various other types of land use. However, such reductions can have serious future implications. Therefore, an assessment of the vegetation cover of urban areas is essential. In this paper, Landsat satellite imageries have been used to study the changes in the vegetation cover of Kolkata, the largest metropolis in eastern India, from 1973 to 2011. The entire area of Kolkata and its surroundings (up to a distance of 10 km) has been divided into four quadrants according to the cardinal directions (northeast, southeast, southwest and northwest) and six concentric rings of 2 km radius each, and from these 24 sectors (four quadrants and six concentric circles), vegetated lands have been identified for analyzing the changes during the study period. There is a constant decrease of vegetation cover from 1973 till date. The outer periphery of the city is characterized by more urban vegetation as compared to the core of the city. Apart from this, the western sector is denser in terms of vegetation than the eastern one.