The purposes of this research were to study 1) the factors affecting the well-being of migrant workers, and 2) the management model for the well-being of migrant workers. This research focused on using mixed methods: quantitative and qualitative research. The samples for the quantitative research consisted of 400 migrant workers from Myanmar, Laos, and Cambodia who received a work permit in the category of labor in the area of Bangkok. A stratified random sampling method and a structural equation modeling analysis were used in this research. Data collection for qualitative research was carried out through in-depth interviews with 17 informants in four different groups: 1) the Inspector general of the Ministry of Labor, 2) six employers whose employees were Cambodian, Laotian, or Burmese migrant workers of at least one nationality, 3) six migrant workers divided into two per nationality, and 4) four district directors. The research results revealed that: 1) life satisfaction had the overall influence on well-being at the highest level, followed by job satisfaction, job resources, job demand, and cross-cultural adaptation respectively, and 2) the management model for wellbeing consisted of three areas: 1) The government sector must regularly organize training and public relations on related issues for personnel within the unit, as well as provide an interpreter to communicate and explain legal matters. 2) Employers must accept migrant workers without insult and provide fair remuneration. And 3) Migrant workers must adapt to Thai culture, be responsible, and have appropriate time management between assignments.