Agglomeration economies have been analyzed in the literature as drivers of economic growth, as these contribute to productivity enhancement. The primary objective of this paper is to ascertain the existence of agglomeration economies, and to examine the extent to which these have contributed to productivity growth in India. Two sources of agglomeration economies are distinguished – (i) at the industry level – localization economies of intra-industry linkage; and (ii) at the regional level – inter-industry urbanization economies. Growth accounting framework is used with agglomeration parameters included in the shift term of a general production function, coefficients of which are estimated through panel data regression. I employ state level data for 25 state economies in India for the period 1980-81 to 2006-07. Results provide evidence that urbanization economies tend to exist; however, there is considerable variation in the sources and magnitude of agglomeration economies across sectors. Results indicate that for service sector, the economies of urbanization exist on a lower level of urbanization, whereas for manufacturing, these economies are present at higher levels. Results support regional diversity more than localization, even if some differences can be seen across sectors.