After reviewing the available literature on internal migration in Bangladesh estimates are presented for the time periods 1941-51, 1951-61 and 1961-74. The data from the 1974 census of Bangladesh and the 1961 census of East Pakistan have been utilized for this exercise. The main finding is that, in the last three decades, the geographical pattern of internal movement has remained nearly the same--a Westward/North-Westward movement. Leaving aside Dacca and Chittagong districts, all the remaining Eastern districts lose population. Sylhet, which gained population in the earlier period, has lost population in the 1961-71 span. There is age selectivity in regard to spatial mobility. While the receiving districts gain people in the 20-49 age interval, they lose people in the 50-59 age group. It is also seen that the districts, which lose population, gain members in the 50-59 age group. This implies that the return migration may be a characteristic of the older population. The male and the female propensities of migration are also different and have undergone change in the last three decades. A regression analysis of inter-district migration for the 1951-51 period was carried out with several explanatory variables. We infer that the inertia and the cost factors retarded the migratory flows. Farm size, intensity of cultivation, age, and labour force participation indicated that there was outmigration from areas of high demand of land to areas of low demand. This may be due to the fragmentation of land holdings emanating from the inheritance pattern and not due to the social change factor. The effect of population density seemed to go against the popular interpretation of population pressure. In fact, the concentration of Hindu population, literacy, and density seemed to go together and may represent a disguised urbanization factor. The model then shows two types of internal migration in Bangladesh-(a) a "conservative" movement to the West/North-West areas of less pressure on land and (b) an "innovating" movement to the districts of Dacca and Chittagong which contain the two major cities of the nation. (excerpt)