Internal migration is now recognized as an important factor in influencing social and economic development, especially in developing countries. Indian censuses record that in 2001, 309 million persons were migrants based on place of last residence, which constitute about 30% of the total population of the country. This is nearly double the number of internal migrants as recorded in the census of 1971 (159 million). This suggests that socio-economic changes in the last three decades have greatly affected the mobility of the population. This paper attempts to provide the trends and patterns of internal migration during 1971-2001 on the basis of census data for that period. Findings show that the composition of internal migration has changed over the years. Moreover, it is observed that the growth of internal migrants differs by sex as well as the streams of migration and the mobility of Indian population has significantly increased during the 1990s.