IOM began its operations in Thailand in 1975, assisting the resettlement of Indo-Chinese refugees to countries offering them permanent residence. With the Kingdom of Thailand joining IOM as a member state in 1986, the organization's cooperation with the Royal Thai Government has expanded to cover all aspects of migration affecting the Kingdom and its neighbours, including labour migration, migration health, counter trafficking, emergency and post crisis, institution building, border management, security and law enforcement.

Today, IOM has a strong presence in Thailand with over 350 personnel working on more than 50 active projects in eleven locations across the country. The IOM Mission in Thailand has a main office in central Bangkok, four sub offices and six other project offices in the Bangkok Metropolitan Area, Chiang Mai, Mae Hong Son, Mae Sariang, Mae Sot and Samut Prakarn.