Using data from the 1960, 1970, and 1980 censuses of Thailand, this paper explores the changing pattern of internal migration. Throughout the period, the census indicates a high degree of stability. Lifetime migration shows a slight rise in each period; recently it has risen in inter- as opposed to intra-regional movement. Five year interprovincial migration increased between 1955-60 and 1965-70 but declined in 1975-80. Between 1970 and 1980 interprovincial migration declined while interregional movement increased. Rural to rural migration declined while urban to urban movement became prevalent. Thus, by 1975-80 internal population redistribution had changed considerably from 1955-1960. Bangkok, the North, and the South had gained population while the Central and Northeast regions lost. Most recently, only Bangkok and the Central regions gained while the others lost population. The greatest loss was that of the Northeast, where net loss to Bangkok and the Central region alone accounted for three-fourths of the gains made by these two areas. These changing distributions are partly related to regional inequalities. Despite development efforts, the Northeast continues as the poorest region, while Bangkok and the contiguous provinces in the Central region profit from high levels of development and the capital's primacy. Migration patterns may also reflect greater reliance on temporary movement, in lieu of long-term migration, especially as transportation networks have improved. Thirty-three references conclude the document. (Author/APG)