The objective of this paper was to study the situation of aged population in Thailand, from 1960 to 2020. Sizes, age-sex structures and changes of the Thai elderly by geographic regions and the country were investigated. The data from 1960 to 2000 population censuses and the projection to 2020 were employed to measure the past and future ageing processes. The findings of this study confirmed an obviously accelerated rate of ageing during the past three decades. The population of Thailand would become a real aged population in the near future.
