This study examines how language diversity is managed at the individual, community, and national level, and the extent to which language diversity management impacts on local people and migrant workers in Thailand, Malaysia, and Singapore. The results will serve as the basis for recommendations to Thailand and other ASEAN countries. Qualitative methods, including in-depth interviews were used in this study. The findings show that Thailand provides for migrant workers and their children in terms of formal and informal education, health care services, work place regulation, and interpreter support. In Malaysia and Singapore, some NGOs and the private sector provide a few English courses and skill development options, but, unlike Thailand, no support for special programmes is provided. This study suggests that, for Thailand, the official and private sectors should consider offering ‚language competence compensation‛ to supplement public service salaries to encourage more Thais to learn other languages, particularly Burmese-Thai/Mon-Thai, so that they can be trained to be interpreters. In addition, the study suggests that curricula for migrant children that are mutually acceptable in both Thailand and Myanmar should be designed; and a ‚Migrant Workers Fund‛ should be set up for migrant well-being and development. ASEAN countries, should adopt a fair and 'win-win' strategy for recruiting migrant workers in both sending and receiving countries, and ASEAN should consider applying a multilingual policy bloc-wide.