This paper discusses the issue of labour supply in five Southeast Asian countries namely Indonesia, Malaysia, Philippines, Singapore, and Thailand. The authors forecast that there will be an oversupply of labour in most of these countries due to the entrance of young people into the labour market. The authors expect that high fertility rates between 1960 and 1980 in these five countries will lead to an oversupply of labour that cannot be met, and will therefore lead to high unemployment. The first part of the paper discusses the labour supply situation in Southeast Asia as a whole, as well as trends in each of the five countries, while the second part looks at factors that affect participation in the labour force.